Catalyst Composition Comprising Shuttling Agent For Tactic/ Atactic Multi-Block Copolymer Formation

ABSTRACT

Copolymers, especially multi-block copolymer containing therein two or more segments or blocks differing in tacticity, are prepared by polymerizing propylene, 4-methyl-1-pentene, or another C 4-8  α-olefin in the presence of a composition comprising the admixture or reaction product resulting from combining: (A) a first metal complex olefin polymerization catalyst, (B) a second metal complex olefin polymerization catalyst capable of preparing polymers differing in tacticity from the polymer prepared by catalyst (A) under equivalent polymerization conditions, and (C) a chain shuttling agent.

CROSS REFERENCE STATEMENT

This application claims the benefit of U.S. Provisional Application No.60/662,937, filed Mar. 17, 2005.

BACKGROUND OF THE INVENTION

The present invention relates to compositions for polymerizingpropylene, 4-methyl-1-pentene, or another C₄₋₈ α-olefin, to form aninterpolymer product having unique physical properties, to a process forpreparing such interpolymers, and to the resulting polymer products. Inanother aspect, the invention relates to methods of using these polymersin applications requiring unique combinations of physical properties. Instill another aspect, the invention relates to the articles preparedfrom these polymers. The inventive polymers comprise two or more regionsor segments (blocks) differing in tacticity causing the polymer topossess unique physical properties. These multi-block copolymers andpolymeric blends comprising the same are usefully employed in thepreparation of solid articles such as moldings, films, sheets, andfoamed objects by molding, extruding, or other processes, and are usefulas components or ingredients in laminates, polymeric blends, and otherend uses. The resulting products are used in the manufacture ofcomponents for automobiles, such as profiles, bumpers and trim parts;packaging materials; electric cable insulation, and other applications.

It has long been known that polymers containing a block-type structureoften have superior properties compared to random copolymers and blends.For example, triblock copolymers of styrene and butadiene (SBS) andhydrogenated versions of the same (SEBS) have an excellent combinationof heat resistance and elasticity. Other block copolymers are also knownin the art. Generally, block copolymers known as thermoplasticelastomers (TPE) have desirable properties due to the presence of “soft”or elastomeric block segments connecting “hard” either crystallizable orglassy blocks in the same polymer. At temperatures up to the melttemperature or glass transition temperature of the hard segments, thepolymers demonstrate elastomeric character. At higher temperatures, thepolymers become flowable, exhibiting thermoplastic behavior. Knownmethods of preparing block copolymers include anionic polymerization andcontrolled free radical polymerization. Unfortunately, these methods ofpreparing block copolymers require sequential monomer addition and batchprocessing and the types of monomers that can be usefully employed insuch methods are relatively limited. For example, in the anionicpolymerization of styrene and butadiene to form a SBS type blockcopolymer, each polymer chain requires a stoichiometric amount ofinitiator and the resulting polymers have extremely narrow molecularweight distribution, Mw/Mn, preferably from 1.0 to 1.3. Additionally,anionic and free-radical processes are relatively slow, resulting inpoor process economics.

It would be desirable to produce block copolymers catalytically, thatis, in a process wherein more than one polymer molecule is produced foreach catalyst or initiator molecule. In addition, it would be highlydesirable to produce block copolymers from propylene,4-methyl-1-pentene, or another C₄₋₈ α-olefin monomer that are generallyunsuited for use in anionic or free-radical polymerizations. In certainof these polymers, it is highly desirable that some or all of thepolymer blocks comprise atactic polymer blocks and some or all of theremaining polymer blocks predominantly comprise tactic, especiallyisotactic propylene, 4-methyl-1-pentene, or other C₄₋₈ α-olefin inpolymerized form, preferably highly stereospecific, especiallyisotactic, polypropylene or 4-methyl-1-pentene homopolymers. Finally, ifwould be highly desirable to be able to use a continuous process forproduction of block copolymers of the present type.

Previous researchers have stated that certain homogeneous coordinationpolymerization catalysts can be used to prepare polymers having asubstantially “block-like” structure by suppressing chain-transferduring the polymerization, for example, by conducting the polymerizationprocess in the absence of a chain transfer agent and at a sufficientlylow temperature such that chain transfer by α-hydride elimination orother chain transfer processes is essentially eliminated. Under suchconditions, the sequential addition of different monomers was said toresult in formation of polymers having sequences or segments ofdifferent monomer content. Several examples of such catalystcompositions and processes are reviewed by Coates, Hustad, and Reinartzin Angew. Chem., Int. Ed., 41, 2236-2257 (2002) as well asUS-A-2003/0114623.

Disadvantageously, such processes require sequential monomer additionand result in the production of only one polymer chain per activecatalyst center, which limits catalyst productivity. In addition, therequirement of relatively low process temperatures increases the processoperating costs, making such processes unsuited for commercialimplementation. Moreover, the catalyst cannot be optimized for formationof each respective polymer type, and therefore the entire processresults in production of polymer blocks or segments of less than maximalefficiency and/or quality. For example, formation of a certain quantityof prematurely terminated polymer is generally unavoidable, resulting inthe forming of blends having inferior polymer properties. Accordingly,under normal operating conditions, for sequentially prepared blockcopolymers having Mw/Mn of 1.5 or greater, the resulting distribution ofblock lengths is relatively inhomogeneous, not a most probabledistribution. Finally, sequentially prepared block copolymers must beprepared in a batch process, limiting rates and increasing costs withrespect to polymerization reactions carried out in a continuous process.

For these reasons, it would be highly desirable to provide a process forproducing olefin copolymers in well defined blocks or segments in aprocess using coordination polymerization catalysts capable of operationat high catalytic efficiencies. In addition, it would be desirable toprovide a process and resulting block or segmented copolymers whereininsertion of terminal blocks or sequencing of blocks within the polymercan be influenced by appropriate selection of process conditions.Finally, it would be desirable to provide a continuous process forproducing multi-block copolymers.

The use of certain metal alkyl compounds and other compounds, such ashydrogen, as chain transfer agents to interrupt chain growth in olefinpolymerizations is well known in the art. In addition, it is known toemploy such compounds, especially aluminum alkyl compounds, asscavengers or as cocatalysts in olefin polymerizations. InMacromolecules, 33, 9192-9199 (2000) the use of certain aluminumtrialkyl compounds as chain transfer agents in combination with certainpaired zirconocene catalyst compositions resulted in polypropylenemixtures containing small quantities of polymer fractions containingboth isotactic and atactic chain segments. In Liu and Rytter,Macromolecular Rapid Comm., 22, 952-956 (2001) and Bruaseth and Rytter,Macromolecules, 36, 3026-3034 (2003) mixtures of ethylene and 1-hexenewere polymerized by a similar catalyst composition containingtrimethylaluminum chain transfer agent. In the latter reference, theauthors summarized the prior art studies in the following manner (somecitations omitted):

-   -   “Mixing of two metallocenes with known polymerization behavior        can be used to control polymer microstructure. Several studies        have been performed of ethene polymerization by mixing two        metallocenes. Common observations were that, by combining        catalysts which separately give polyethene with different Mw,        polyethene with broader and in some cases bimodal MWD can be        obtained. [S]oares and Kim (J. Polym. Sci., Part A: Polym.        Chem., 38, 1408-1432 (2000)) developed a criterion in order to        test the MWD bimodality of polymers made by dual single-site        catalysts, as exemplified by ethene/1-hexene copolymerization of        the mixtures Et(Ind)₂ZrCl₂/Cp₂HfCl₂ and Et(Ind)₂ZrCl₂/CGC        (constrained geometry catalyst) supported on silica. Heiland and        Kaminsky (Makromol. Chem., 193, 601-610 (1992)) studied a        mixture of Et-(Ind)₂ZrCl₂ and the hafnium analogue in        copolymerization of ethene and 1-butene.

These studies do not contain any indication of interaction between thetwo different sites, for example, by readsorption of a terminated chainat the alternative site. Such reports have been issued, however, forpolymerization of propene. Chien et al. (J. Polym. Sci., Part A: Polym.Chem., 37, 2439-2445 (1999), Makromol., 30, 3447-3458 (1997)) studiedpropene polymerization by homogeneous binary zirconocene catalysts. Ablend of isotactic polypropylene (1-PP), atactic polypropylene (a-PP),and a stereoblock fraction (1-PP-b-a-PP) was obtained with a binarysystem comprising an isospecific and an aspecific precursor with aborate and TIBA as cocatalyst. By using a binary mixture of isospecificand syndiospecific zirconocenes, a blend of isotactic polypropylene(i-PP), syndiotactic polypropylene (s-PP), and a stereoblock fraction(i-PP-b-s-PP) was obtained. The mechanism for formation of thestereoblock fraction was proposed to involve the exchange of propagatingchains between the two different catalytic sites. Przybyla and Fink(Acta Polym., 50, 77-83 (1999)) used two different types of metallocenes(isospecific and syndiospecific) supported on the same silica forpropene polymerization. They reported that, with a certain type ofsilica support, chain transfer between the active species in thecatalyst system occurred, and stereoblock PP was obtained. Lieber andBrintzinger (Macromol. 3, 9192-9199 (2000)) have proposed a moredetailed explanation of how the transfer of a growing polymer chain fromone type of metallocene to another occurs. They studied propenepolymerization by catalyst mixtures of two different ansa-zirconocenes.The different catalysts were first studied individually with regard totheir tendency toward alkyl-polymeryl exchange with the alkylaluminumactivator and then pairwise with respect to their capability to producepolymers with a stereoblock structure. They reported that formation ofstereoblock polymers by a mixture of zirconocene catalysts withdifferent stereoselectivities is contingent upon an efficient polymerylexchange between the Zr catalyst centers and the Al centers of thecocatalyst.”

Brusath and Rytter then disclosed their own observations using pairedzirconocene catalysts to polymerize mixtures of ethylene/1-hexene andreported the effects of the influence of the dual site catalyst onpolymerization activity, incorporation of comonomer, and polymermicrostructure using methylalumoxane cocatalyst.

Analysis of the foregoing results indicate that Rytter and coworkerslikely failed to utilize combinations of catalyst, cocatalyst, and thirdcomponents that were capable of readsorption of the polymer chain fromthe chain transfer agent onto both of the active catalytic sites, thatis, two-way readsorption. While indicating that chain termination due tothe presence of trimethylaluminum likely occurred with respect topolymer formed from the catalyst incorporating minimal comonomer, andthereafter that polymeryl exchange with the more open catalytic sitefollowed by continued polymerization likely occurred, evidence of thereverse flow of polymer ligands appeared to be lacking in the reference.In fact, in a later communication, Rytter, et. al., Polymer, 45,7853-7861 (2004), it was reported that no chain transfer between thecatalyst sites actually took place in the earlier experiments. Similarpolymerizations were reported in WO98/34970.

In U.S. Pat. Nos. 6,380,341 and 6,169,151, use of a “fluxional”metallocene catalyst, that is a metallocene capable of relatively facileconversion between two stereoisomeric forms having differingpolymerization characteristics such as differing reactivity ratios wassaid to result in production of olefin copolymers having a “blocky”structure. Disadvantageously, the respective stereoisomers of suchmetallocenes generally fail to possess significant difference in polymerformation properties and are incapable of forming both highlycrystalline and amorphous block copolymer segments, for example, from agiven monomer mixture under fixed reaction conditions. Moreover, becausethe relative ratio of the two “fluxional” forms of the catalyst cannotbe varied, there is no ability, using “fluxional” catalysts, to varypolymer block composition or the ratio of the respective blocks.Finally, prior art methods for olefin block copolymerization have beenincapable of readily controlling the sequencing of the various polymerblocks, and in particular controlling the nature of the terminatingblock or segment of a multi-block copolymer. For certain applications,it is desirable to produce polymers having terminal blocks that arehighly crystalline, that are functionalized or more readilyfunctionalized, or that possess other distinguishing properties. Forexample, it is believed that polymers wherein the terminal segments orblocks are highly isotactic possess improved abrasion resistance. Inaddition, polymers wherein the atactic blocks are internal or primarilyconnected between tactic, especially isotactic, blocks, have improvedphysical properties, such as abrasion resistance.

In JACS. 2004, 126, 10701-10712, Gibson, et al discuss the effects of“catalyzed living polymerization” on molecular weight distribution. Theauthors define catalyzed living polymerization in this manner:

“ . . . if chain transfer to aluminum constitutes the sole transfermechanism and the exchange of the growing polymer chain between thetransition metal and the aluminum centers is very fast and reversible,the polymer chains will appear to be growing on the aluminum centers.This can then reasonably be described as a catalyzed chain growthreaction on aluminum . . . . An attractive manifestation of this type ofchain growth reaction is a Poisson distribution of product molecularweights, as opposed to the Schulz-Flory distribution that arises whenβ-H transfer accompanies propagation.”

The authors reported the results for the catalyzed livinghomopolymerization of ethylene using an iron containing catalyst incombination with ZnEt₂, ZnMe₂, or Zn(i-Pr)₂. Homoleptic alkyls ofaluminum, boron, tin, lithium, magnesium and lead did not inducecatalyzed chain growth. Using GaMe₃ as cocatalyst resulted in productionof a polymer having a narrow molecular weight distribution. However,after analysis of time-dependent product distribution, the authorsconcluded this reaction was, “not a simple catalyzed chain growthreaction.” The reference fails to disclose the use of two or morecatalysts in combination with a chain shuttling agent to makemulti-block copolymers. Similar processes employing single catalystshave been described in U.S. Pat. Nos. 5,210,338, 5,276,220, and6,444,867.

Earlier workers have claimed to have formed block copolymers using asingle Ziegler-Natta type catalyst in multiple reactors arranged inseries, see for example U.S. Pat. Nos. 3,970,719 and 4,039,632.Additional Ziegler-Natta based processes and polymers are disclosed inU.S. Pat. Nos. 4,971,936; 5,089,573; 5,118,767; 5,118,768; 5,134,209;5,229,477; 5,270,276; 5,270,410; 5,294,581; 5,543,458; 5,550,194; and5,693,713, as well as in EP-A-470,171 and EP-A-500,530.

Despite the advances by the foregoing researchers, there remains a needin the art for a polymerization process that is capable of preparingblock like copolymers, especially multi-block copolymers, and mostespecially linear multi-block copolymers predominantly comprisingpropylene, 4-methyl-1-pentene, or another C₄₋₈ α-olefin in high yieldand selectivity. Moreover, it would be desirable if there were providedan improved process for preparing such multi-block copolymers,especially linear multi-block copolymers of propylene or4-methyl-1-pentene, or another C₄ or higher α-olefin(s), by the use of ashuttling agent. In addition it would be desirable to provide such animproved process that is capable of preparing such multi-blockcopolymers, especially linear multi-block copolymers, having arelatively narrow molecular weight distribution. It would further bedesirable to provide an improved process for preparing such copolymershaving more than two segments or blocks. Furthermore, it would bedesirable to provide a process for identifying combinations of catalystsand chain shuttling agents capable of making such multi-blockcopolymers. Even further, it would be desirable to provide a process forindependent control of the order of the various polymer blocks,especially a process for preparing multi-block copolymers comprisedpredominantly of propylene or 4-methyl-1-pentene, containing terminalblocks having high stereospecificity and/or functionality. Finally, itwould be desirable to provide an improved process for preparing any ofthe foregoing desirable polymer products in a continuous process,especially a continuous solution polymerization process. Highlydesirably, such process allows for independent control of the quantityand/or identity of the shuttling agent(s) and/or catalysts used.

SUMMARY OF THE INVENTION

According to the present invention there are now provided a compositionfor use in the polymerization of one or more C₃₋₃₀ α-olefin additionpolymerizable monomers and optionally one or more C₄₋₃₀ cyclo-olefins ordiolefins, to form a high molecular weight, segmented copolymer(multi-block copolymer), said copolymer containing therein two or more,preferably three or more segments or blocks differing in tacticity, thecomposition comprising the admixture or reaction product resulting fromcombining:

(A) a first olefin polymerization catalyst,

(B) a second olefin polymerization catalyst capable of preparing apolymer differing in tacticity or crystallinity from the polymerprepared by catalyst (A) under equivalent polymerization conditions, and

-   (C) a chain shuttling agent; and

preferably the admixture or reaction product resulting from combining:

(A) a first olefin polymerization catalyst that under the conditions ofpolymerization forms a tactic polymer of one or more C₃₋₃₀ α-olefins,

(B) a second olefin polymerization catalyst that under the conditions ofpolymerization forms a polymer having a tacticity less than 95 percent,preferably less than 90 percent, more preferably less than 75 percent,and most preferably less than 50 percent of the polymer formed bycatalyst (A), and

(C) a chain shuttling agent.

In another embodiment of the invention, there is provided a method forselecting an admixture of catalysts (A) and (B) and chain shuttlingagent (C) capable of producing multi-block copolymers according to theinvention, especially such polymers comprising propylene,4-methyl-1-pentene, or another C₄₋₈ α-olefin as the sole polymerizedolefin. Highly desirably, the resulting polymer comprises alternatingblocks of generally atactic polypropylene with blocks of generallyisotactic polypropylene or alternating blocks of generally atacticpoly-4-methyl-1-pentene with blocks of generally isotacticpoly-4-methyl-1-pentene. Also included are polymers of the foregoingtype, wherein one or more polymer sequences therein are furthercharacterized by the presence of regio-irregular monomer addition,preferably due to 2,1- or 3,1-monomer insertion errors or otherinsertion errors.

In a further embodiment of the present invention there is provided aprocess for preparing a high molecular weight, segmented, copolymerconsisting essentially of propylene, 4-methyl-1-pentene, or another C₄₋₈α-olefin in polymerized form, said process comprising contactingpropylene, 4-methyl-1-pentene, or another C₄₋₈ α-olefin under additionpolymerization conditions with a composition comprising:

the admixture or reaction product resulting from combining:

(A) a first olefin polymerization catalyst,

(B) a second olefin polymerization catalyst capable of preparingpolymers differing in tacticity from the polymer prepared by catalyst(A) under equivalent polymerization conditions, and

(C) a chain shuttling agent.

Preferably, the foregoing process takes the form of a continuoussolution process for forming block copolymers, especially multi-blockcopolymers, preferably linear multi-block copolymers of propylene,4-methyl-1-pentene or another C₄₋₂₀ olefin, and most especiallypropylene, using multiple catalysts that are incapable ofinterconversion. That is the catalysts are chemically distinct. Undercontinuous solution polymerization conditions, the process is ideallysuited for polymerization of monomers at high monomer conversions. Underthese polymerization conditions, shuttling from the chain shuttlingagent to the catalyst becomes advantaged compared to chain growth, andmulti-block copolymers, especially linear multi-block copolymersaccording to the invention are formed in high efficiency.

In another embodiment of the invention there is provided a segmentedcopolymer (multi-block copolymer), especially such a copolymercomprising propylene, 4-methyl-1-pentene, or another C₄₋₈ α-olefin inpolymerized form, said copolymer containing therein two or more,preferably three or more segments differing in tacticity orcrystallinity. Desirably, the resulting polymer comprises alternatingblocks of generally atactic polypropylene with blocks of stereospecific,preferably isotactic polypropylene or alternating blocks of generallyatactic poly-4-methyl-1-pentene with blocks of stereospecific,preferably isotactic poly-4-methyl-1-pentene. Highly preferably thecopolymer possesses a molecular weight distribution, Mw/Mn, of less than3.0, preferably less than 2.8.

In yet another embodiment of the invention, there are providedfunctionalized derivatives of the foregoing segmented or multi-blockcopolymers.

In a still further embodiment of the present invention, there isprovided a polymer mixture comprising: (1) an organic or inorganicpolymer, preferably a homopolymer of propylene and/or a copolymer ofethylene and a copolymerizable comonomer, a homopolymer of4-methyl-1-pentene, or a highly crystalline polyethylene, and (2) a highmolecular weight, multi-block copolymer according to the presentinvention or prepared according to the process of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic representation of the process of polymer chainshuttling involving two catalyst sites.

DETAILED DESCRIPTION OF THE INVENTION

All references to the Periodic Table of the Elements herein shall referto the Periodic Table of the Elements, published and copyrighted by CRCPress, Inc., 2003. Also, any references to a Group or Groups shall be tothe Group or Groups reflected in this Periodic Table of the Elementsusing the IUPAC system for numbering groups. Unless stated to thecontrary, implicit from the context, or customary in the art, all partsand percents are based on weight. For purposes of United States patentpractice, the contents of any patent, patent application, or publicationreferenced herein are hereby incorporated by reference in their entirety(or the equivalent US version thereof is so incorporated by reference)especially with respect to the disclosure of synthetic techniques,definitions (to the extent not inconsistent with any definitionsprovided herein) and general knowledge in the art.

The term “comprising” and derivatives thereof is not intended to excludethe presence of any additional component, step or procedure, whether ornot the same is disclosed herein. In order to avoid any doubt, allcompositions claimed herein through use of the term “comprising” mayinclude any additional additive, adjuvant, or compound whether polymericor otherwise, unless stated to the contrary. In contrast, the term,“consisting essentially of” excludes from the scope of any succeedingrecitation any other component, step or procedure, excepting those thatare not essential to operability. The term “consisting of” excludes anycomponent, step or procedure not specifically delineated or listed. Theterm “or”, unless stated otherwise, refers to the listed membersindividually as well as in any combination.

The term “polymer”, includes both conventional homopolymers, that is,homogeneous polymers prepared from a single monomer, and copolymers(interchangeably referred to herein as interpolymers), meaning polymersprepared by reaction of at least two monomers or otherwise containingchemically differentiated segments or blocks therein even if formed froma single monomer. More specifically, the term “polyethylene” includeshomopolymers of ethylene and copolymers of ethylene and one or moreC₃₋₃₀ α-olefins in which ethylene comprises at least 50 mole percent.The term “propylene copolymer” or “propylene interpolymer” means acopolymer comprising propylene and optionally one or morecopolymerizable comonomers, wherein propylene comprises a plurality ofthe polymerized monomer units of at least one block or segment in thepolymer, preferably at least 90 mole percent, more preferably at least95 mole percent, and most preferably at least 98 mole percent. A polymermade primarily from a different α-olefin, such as 4-methyl-1-pentenewould be named similarly. The term “crystalline” if employed, refers toa polymer or polymer block that possesses a first order transition orcrystalline melting point (Tm) as determined by differential scanningcalorimetry (DSC) or equivalent technique. The term may be usedinterchangeably with the term “semicrystalline”. The term “amorphous”refers to a polymer lacking a crystalline melting point. The term,“isotactic” or “syndiotactic” refers to polymer repeat units having atleast 70 percent isotactic or syndiotactic pentads as determined by¹³C-NMR analysis. “Highly isotactic” or “highly syndiotactic” is definedas polymers having at least 90 percent isotactic or syndiotacticpentads. The term “tactic” means polymer repeat units that are eitherisotactic or syndiotactic, and “highly tactic” refers to polymer repeatunits that are either highly isotactic or highly syndiotactic. Tacticpolymers may be interchangeably referred to as crystalline orsemi-crystalline polymers, whereas atactic polymers may beinterchangeably referred to herein as amorphous.

The term “multi-block copolymer” or “segmented copolymer” refers to apolymer comprising two or more chemically distinct regions or segments(referred to as “blocks”) preferably joined in a linear manner, that is,a polymer comprising chemically differentiated units which are joinedend-to-end with respect to polymerized ethylenic functionality, ratherthan in pendent or grafted fashion. In the present invention, the blocksdiffer in the type or degree of tacticity (atactic segments as well asisotactic or syndiotactic segments) and optionally regio-regularity.Desirably the polymers are prepared from a single polymerizable monomer,most preferably propylene. Compared to block copolymers of the priorart, including copolymers produced by fluxional catalysts, thecopolymers of the invention are characterized by unique distributions ofboth polymer polydispersity (PDI or Mw/Mn), block length distribution,and/or block number distribution, due, in a preferred embodiment, to theeffect of the shuttling agent(s) in combination with multiple catalysts.More specifically, when produced in a continuous process, the polymersdesirably possess PDI from 1.7 to 2.9, preferably from 1.8 to 2.5, morepreferably from 1.8 to 2.2, and most preferably from 1.8 to 2.1. Whenproduced in a batch or semi-batch process, the polymers desirablypossess PDI from 1.0 to 2.9, preferably from 1.3 to 2.5, more preferablyfrom 1.4 to 2.2, and most preferably from 1.4 to 2.1.

Because the respective distinguishable segments or blocks joined intosingle polymer chains, the polymer cannot be completely fractionatedusing standard selective extraction techniques. For example, polymerscontaining regions that are highly tactic and regions that arerelatively atactic cannot be selectively extracted or fractionated usingdiffering solvents. In a preferred embodiment the quantity ofextractable polymer using either a dialkyl ether- or an alkane-solventis less than 10 percent, preferably less than 7 percent, more preferablyless than 5 percent and most preferably less than 2 percent of the totalpolymer weight.

In addition, the multi-block copolymers of the invention desirablypossess a PDI fitting a Schutz-Flory distribution rather than a Poissondistribution. The use of the present polymerization process results in aproduct having both a polydisperse block distribution as well as apolydisperse distribution of block sizes. This ultimates in theformation of polymer products having improved and distinguishablephysical properties. The theoretical benefits of a polydisperse blockdistribution have been previously modeled and discussed in Potemkin,Physical Review E (1998) 57(6), p. 6902-6912, and Dobrynin, J. Chem.Phys. (1997) 107(21), p 9234-9238.

In a further embodiment, the polymers of the invention, especially thosemade in a continuous, solution polymerization reactor, possess a mostprobable distribution of block lengths. Most preferred polymersaccording to the invention are multi-block copolymers containing 4 ormore blocks or segments including terminal blocks.

The following mathematical treatment of the resulting polymers is basedon theoretically derived parameters that are believed to apply to thepresent invented polymers and demonstrate that, especially in asteady-state, continuous, well-mixed reactor, the block lengths of theresulting polymer prepared using 2 or more catalysts will each conformto a most probable distribution, derived in the following manner,wherein p_(i) is the probability of propagation with respect to blocksequences from catalyst i. The theoretical treatment is based onstandard assumptions and methods known in the art and used in predictingthe effects of polymerization kinetics on molecular architecture,including the use of mass action reaction rate expressions that are notaffected by chain or block lengths. Such methods have been previouslydisclosed in W. H. Ray, J. Macromol. Sci. Rev. Macromol. Chem., C8, 1(1972) and A. E. Hamielec and J. F. MacGregor, “Polymer ReactionEngineering”, K. H. Reichert and W. Geisler, Eds., Hanser, Munich, 1983.In addition it is assumed that adjacent sequences formed by the samecatalyst form a single block. For catalyst i, the fraction of sequencesof length n is given by X_(i)[n], where n is an integer from 1 toinfinity representing the number of monomer units in the block.

$\begin{matrix}{{X_{i}\lbrack n\rbrack} = {\left( {1 - p_{i}} \right)p_{i}^{({n - 1})}}} & {{most}\mspace{14mu} {probable}\mspace{14mu} {distribution}} \\\; & {{of}\mspace{14mu} {block}\mspace{14mu} {lengths}} \\{N_{i} = \frac{1}{1 - p_{i}}} & {{number}\mspace{14mu} {average}\mspace{14mu} {block}\mspace{14mu} {length}}\end{matrix}$

Each catalyst has a probability of propagation (p_(i)) and forms apolymer segment having a unique average block length and distribution.In a most preferred embodiment, the probability of propagation isdefined as:

$p_{i} = \frac{{Rp}\lbrack i\rbrack}{{{Rp}\lbrack i\rbrack} + {{Rt}\lbrack i\rbrack} + {{Rs}\lbrack i\rbrack} + \left\lbrack C_{i} \right\rbrack}$

for each catalyst i={1,2 . . . }, where,

Rp[i]=Rate of monomer consumption by catalyst i, (moles/L),

Rt[i]=Total rate of chain transfer and termination for catalyst i,(moles/L),

Rs[i]=Rate of chain shuttling with dormant polymer to other catalysts,(moles/L), and

[C_(i)]=Concentration of catalyst i (moles/L).

Dormant polymer chains refers to polymer chains that are attached to aCSA.

The overall monomer consumption or polymer propagation rate, Rp[i], isdefined using an apparent rate constant, k_(pi) , multiplied by a totalmonomer concentration, [M], as follows:

Rp[i]=θ k_(pi) [M][C_(i)]

The total chain transfer rate is given below including values for chaintransfer to hydrogen (H₂), beta hydride elimination, and chain transferto chain shuttling agent (CSA). The reactor residence time is given by θand each subscripted k value is a rate constant.

Rt[i]=θk _(H2i) [H ₂ ][C _(i) ]+θk _(βi) [C _(i) ]+θk _(ai)[CSA][C _(i)]

For a dual catalyst system, the rate of chain shuttling of polymerbetween catalysts 1 and 2 is given as follows:

Rs[1]=Rs[2]=θk_(a1)[CSA]θk_(a2)[C₁][C₂].

If more than 2 catalysts are employed then added terms and complexity inthe theoretical relation for Rs[i] result, but the ultimate conclusionthat the resulting block length distributions are most probable isunaffected.

As used herein with respect to a chemical compound, unless specificallyindicated otherwise, the singular includes all isomeric forms and viceversa (for example, “hexane”, includes all isomers of hexaneindividually or collectively). The terms “compound” and “complex” areused interchangeably herein to refer to organic-, inorganic- andorganometal compounds. The term, “atom” refers to the smallestconstituent of an element regardless of ionic state, that is, whether ornot the same bears a charge or partial charge or is bonded to anotheratom. The term “heteroatom” refers to an atom other than carbon orhydrogen. Preferred heteroatoms include: F, Cl, Br, N, O, P, B, S, Si,Sb, Al, Sn, As, Se and Ge. The term “amorphous” refers to a polymerlacking a crystalline melting point as determined by differentialscanning calorimetry (DSC) or equivalent technique.

The term, “hydrocarbyl” refers to univalent substituents containing onlyhydrogen and carbon atoms, including branched or unbranched, saturatedor unsaturated, cyclic, polycyclic or noncyclic species. Examplesinclude alkyl-, cycloalkyl-, alkenyl-, alkadienyl-, cycloalkenyl-,cycloalkadienyl-, aryl-, and alkynyl-groups. “Substituted hydrocarbyl”refers to a hydrocarbyl group that is substituted with one or morenonhydrocarbyl substituent groups. The terms, “heteroatom containinghydrocarbyl” or “heterohydrocarbyl” refer to univalent groups in whichat least one atom other than hydrogen or carbon is present along withone or more carbon atom and one or more hydrogen atoms. The term“heterocarbyl” refers to groups containing one or more carbon atoms andone or more heteroatoms and no hydrogen atoms. The bond between thecarbon atom and any heteroatom as well as the bonds between any twoheteroatoms, may be a single or multiple covalent bond or a coordinatingor other donative bond. Thus, an alkyl group substituted with aheterocycloalkyl-, aryl-substituted heterocycloalkyl-, heteroaryl-,alkyl-substituted heteroaryl-, alkoxy-, aryloxy-, dihydrocarbylboryl-,dihydrocarbylphosphino-, dihydrocarbylamino-, trihydrocarbylsilyl-,hydrocarbylthio-, or hydrocarbylseleno-group is within the scope of theterm heteroalkyl. Examples of suitable heteroalkyl groups includecyanomethyl-, benzoylmethyl-, (2-pyridyl)methyl-, andtrifluoromethyl-groups.

As used herein the term “aromatic” refers to a polyatomic, cyclic,conjugated ring system containing (4δ+2) π-electrons, wherein 6 is aninteger greater than or equal to 1. The term “fused” as used herein withrespect to a ring system containing two or more polyatomic, cyclic ringsmeans that with respect to at least two rings thereof, at least one pairof adjacent atoms is included in both rings. The term “aryl” refers to amonovalent aromatic substituent which may be a single aromatic ring ormultiple aromatic rings which are fused together, linked covalently, orlinked to a common group such as a methylene or ethylene moiety.Examples of aromatic ring(s) include phenyl, naphthyl, anthracenyl, andbiphenyl, among others.

“Substituted aryl” refers to an aryl group in which one or more hydrogenatoms bound to any carbon is replaced by one or more functional groupssuch as alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl,heterocycloalkyl, substituted heterocycloalkyl, halogen, alkylhalos (forexample, CF₃), hydroxy, amino, phosphido, alkoxy, amino, thio, nitro,and both saturated and unsaturated cyclic hydrocarbons which are fusedto the aromatic ring(s), linked covalently or linked to a common groupsuch as a methylene or ethylene moiety. The common linking group mayalso be a carbonyl as in benzophenone or oxygen as in diphenylether ornitrogen in diphenylamine.

Monomers

Suitable monomers for use in preparing the polymers of the presentinvention include propylene, 4-methyl-1-pentene, or other C₄₋₈ α-olefin,and optionally one or more copolymerizable comonomers, provided that theobjects of the invention, preparation of a multi-block copolymercontaining alternating blocks of differing tacticity are obtained.Examples of suitable comonomers include ethylene and straight-chain orbranched α-olefins of 4 to 30, preferably 4 to 20 carbon atoms, such as1-butene, 1-pentene, 3-methyl-1-butene, 1-hexene, 4-methyl-1-pentene,3-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene,1-hexadecene, 1-octadecene and 1-eicosene; cycloolefins of 3 to 30,preferably 3 to 20 carbon atoms, such as cyclopentene, cycloheptene,norbornene, 5-methyl-2-norbornene, tetracyclododecene, and2-methyl-1,4,5,8-dimethano-1,2,3,4,4a,5,8,8a-octahydronaphthalene; di-and poly-olefins, such as butadiene, isoprene, 4-methyl-1,3-pentadiene,1,3-pentadiene, 1,4-pentadiene, 1,S-hexadiene, 1,4-hexadiene,1,3-hexadiene, 1,3-octadiene, 1,4-octadiene, 1,5-octadiene,1,6-octadiene, 1,7-octadiene, ethylidene norbornene, vinyl norbornene,dicyclopentadiene, 7-methyl-1,6-octadiene,4-ethylidene-8-methyl-1,7-nonadiene, and 5,9-dimethyl-1,4,8-decatriene;aromatic vinyl compounds such as mono or poly alkylstyrenes (includingstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene,o,p-dimethylstyrene, o-ethylstyrene, m-ethylstyrene and p-ethylstyrene),and functional group-containing derivatives, such as methoxystyrene,ethoxystyrene, vinylbenzoic acid, methyl vinylbenzoate, vinylbenzylacetate, hydroxystyrene, o-chlorostyrene, p-chlorostyrene,divinylbenzene, 3-phenylpropene, 4-phenylpropene, α-methylstyrene,vinylchloride, 1,2-difluoroethylene, 1,2-dichloroethylene,tetrafluoroethylene, and 3,3,3-trifluoro-1-propene.

Chain Shuttling Agents

The term, “shuttling agent” refers to a compound or mixture of compoundsemployed in the composition of the present invention that is capable ofcausing polymeryl exchange between at least two active catalyst sites ofthe catalysts included in the composition under the conditions of thepolymerization. That is, transfer of a polymer fragment occurs both toand from one or more of the active catalyst sites. In contrast to ashuttling agent, a “chain transfer agent” causes termination of polymerchain growth and amounts to a one-time transfer of growing polymer fromthe catalyst to the transfer agent. Preferably, the shuttling agent hasan activity ratio R_(A-B)/R_(B-A) of from 0.01 and 100, more preferablyfrom 0.1 to 10, most preferably from 0.5 to 2.0, and most highlypreferably from 0.8 to 1.2, wherein R_(A-B) is the rate of polymeryltransfer from catalyst A active site to catalyst B active site via theshuttling agent, and R_(B-A) is the rate of reverse polymeryl transfer,that is, the rate of exchange starting from the catalyst B active siteto catalyst A active site via the shuttling agent. Desirably, theintermediate formed between the shuttling agent and the polymeryl chainis sufficiently stable that chain termination is relatively rare.Desirably, less than 90 percent, preferably less than 75 percent, morepreferably less than 50 percent and most desirably less than 10 percentof shuttle-polymeryl products are terminated prior to attaining 3distinguishable polymer segments or blocks. Ideally, the rate of chainshuttling (defined by the time required to transfer a polymer chain froma catalyst site to the chain shuttling agent and then back to a catalystsite) is equivalent to or faster than the rate of polymer termination,even up to 10 or even 100 times faster than the rate of polymertermination. This permits polymer block formation on the same time scaleas polymer propagation.

By selecting different combinations of catalysts having differingpolymerization ability, and by pairing various shuttling agents ormixtures of agents with these catalyst combinations, polymer productshaving segments of different tacticity or regio-error, different blocklengths, and different numbers of such segments or blocks in eachcopolymer can be prepared. For example, if the activity of the shuttlingagent is low relative to the catalyst polymer chain propagation rate ofone or more of the catalysts, longer block length multi-block copolymersand polymer blends may be obtained. Contrariwise, if shuttling is veryfast relative to polymer chain propagation, a copolymer having a morerandom chain structure and shorter block lengths is obtained. Anextremely fast shuttling agent may produce a multi-block copolymerhaving substantially random copolymer properties. By proper selection ofboth catalyst mixture and shuttling agent, relatively pure blockcopolymers, copolymers containing relatively large polymer segments orblocks, and/or blends of the foregoing with various homopolymers and/orcopolymers can be obtained.

A suitable composition comprising Catalyst A, Catalyst B, and a chainshuttling agent can be selected for this invention by the followingmulti-step procedure specially adapted for block differentiation basedon tacticity or regio-error content:

I. One or more addition polymerizable C₃₋₃₀ α-olefin monomers arepolymerized using a mixture comprising a potential catalyst and apotential chain shuttling agent. This polymerization test is desirablyperformed using a batch or semi-batch reactor (that is, without resupplyof catalyst or shuttling agent), preferably with relatively constantmonomer concentration, operating under solution polymerizationconditions, typically using a molar ratio of catalyst to chain shuttlingagent from 1:5 to 1:500. After forming a suitable quantity of polymer,the reaction is terminated by addition of a catalyst poison and thepolymer's properties (tacticity and optionally regio-error content) aremeasured.

II. The foregoing polymerization and polymer testing are repeated forseveral different reaction times, providing a series of polymers havinga range of yields and PDI values.

III. Catalyst/shuttling agent pairs demonstrating significant polymertransfer both to and from the shuttling agent are characterized by apolymer series wherein the minimum PDI is less than 2.0, more preferablyless than 1.5, and most preferably less than 1.3. Furthermore, if chainshuttling is occurring, the Mn of the polymer will increase, preferablynearly linearly, as conversion is increased. Most preferredcatalyst/shuttling agent pairs are those giving polymer Mn as a functionof conversion (or polymer yield) fitting a line with a statisticalprecision (R²) of greater than 0.95, preferably greater than 0.99.

Steps I-III are then carried out for one or more additional pairings ofpotential catalysts and/or putative shuttling agents.

A suitable composition comprising Catalyst A, Catalyst B, and one ormore chain shuttling agents according to the invention is then selectedsuch that the two catalysts each undergo chain shuttling with one ormore of the chain shuttling agents, and Catalyst A has a greatercapacity of selectively forming stereospecific polymer compared toCatalyst B under the reaction conditions chosen. Most preferably, atleast one of the chain shuttling agents undergoes polymer transfer inboth the forward and reverse directions (as identified in the foregoingtest) with both Catalyst A and Catalyst B. In addition, it is preferablethat the chain shuttling agent does not reduce the catalyst activity(measured in weight of polymer produced per weight of catalyst per unittime) of either catalyst (compared to activity in the absence of ashuttling agent) by more than 60 percent, more preferably such catalystactivity is not reduced by more than 20 percent, and most preferablycatalyst activity of at least one of the catalysts is increased comparedto the catalyst activity in the absence of a shuttling agent.

Alternatively, it is also possible to detect desirablecatalyst/shuttling agent pairs by performing a series of polymerizationsunder standard batch reaction conditions and measuring the resultingpolymer properties. Suitable shuttling agents are characterized bylowering of the resultant Mn without significant broadening of PDI orloss of activity (reduction in yield or rate).

The foregoing tests are readily adapted to rapid throughput screeningtechniques using automated reactors and analytic probes and to formationof polymer blocks having different distinguishing properties(syndiotacticity, isotacticity, and optionally regio-error content). Forexample, a number of potential shuttling agent candidates can bepre-identified or synthesized in situ by combination of variousorganometal compounds with various proton sources and the compound orreaction product added to a polymerization reaction employing an olefinpolymerization catalyst composition. Several polymerizations areconducted at varying molar ratios of shuttling agent to catalyst. As aminimum requirement, suitable shuttling agents are those that produce aminimum PDI of less than 2.0 in variable yield experiments as describedabove, while not significantly adversely affecting catalyst activity,and preferably improving catalyst activity, as above described.

Regardless of the method for identifying, a priori, a shuttling agent,the term is meant to refer to a compound that is capable of preparingthe presently identified multi-block copolymers or usefully employedunder the polymerization conditions herein disclosed. Highly desirably,multi-block copolymers having an average number of blocks or segmentsper average chain (as defined as the average number of blocks ofdifferent composition divided by the Mn of the polymer) greater than 3.0more preferably greater than 3.5, even more preferably greater than 4.0,and less than 25, preferably less than 15, more preferably less than10.0, most preferably less than 8.0 are formed according to theinvention.

Suitable shuttling agents for use herein include Group 1, 2, 12 or 13metal compounds or complexes containing at least one C₁₋₂₀ hydrocarbylgroup, preferably hydrocarbyl substituted aluminum, gallium or zinccompounds containing from 1 to 12 carbons in each hydrocarbyl group, andreaction products thereof with a proton source. Preferred hydrocarbylgroups are alkyl groups, preferably linear or branched, C₂₋₈ alkylgroups. Most preferred shuttling agents for use in the present inventionare trialkyl aluminum and dialkyl zinc compounds, especiallytriethylaluminum, tri(i-propyl)aluminum, tri(1-butyl)aluminum,tri(n-hexyl)aluminum, tri(n-octyl)aluminum, triethylgallium, ordiethylzinc. Additional suitable shuttling agents include the reactionproduct or mixture formed by combining the foregoing organometalcompound, preferably a tri(C₁₋₈) alkyl aluminum or di(C₁₋₈) alkyl zinccompound, especially triethylaluminum, tri(i-propyl)aluminum,tri(1-butyl)aluminum, tri(n-hexyl)aluminum, tri(n-octyl)aluminum, ordiethylzinc, with less than a stoichiometric quantity (relative to thenumber of hydrocarbyl groups) of a secondary amine or a hydroxylcompound, especially bis(trimethylsilyl)amine,t-butyl(dimethyl)siloxane, 2-hydroxymethylpyridine, di(n-pentyl)amine,2,6-di(t-butyl)phenol, ethyl(1-naphthyl)amine,bis(2,3,6,7-dibenzo-1-azacycloheptaneamine), or 2,6-diphenylphenol.Desirably, sufficient amine or hydroxyl reagent is used such that onehydrocarbyl group remains per metal atom. The primary reaction productsof the foregoing combinations most desired for use in the presentinvention as shuttling agents are n-octylaluminumdi(bis(trimethylsilyl)amide), i-propylaluminumbis(dimethyl(t-butyl)siloxide), and n-octylaluminumdi(pyridinyl-2-methoxide), i-butylaluminumbis(dimethyl(t-butyl)siloxane), i-butylaluminumbis(di(trimethylsilyl)amide), n-octylaluminum di(pyridine-2-methoxide),i-butylaluminum bis(di(n-pentyl)amide), n-octylaluminumbis(2,6-di-t-butylphenoxide), n-octylaluminumdi(ethyl(1-napththyl)amide), ethylaluminum bis(t-butyldimethylsiloxide),ethylaluminum di(bis(trimethylsilyl)amide), ethylaluminumbis(2,3,6,7-dibenzo-1-azacycloheptaneamide), n-octylaluminumbis(2,3,6,7-dibenzo-1-azacycloheptaneamide), n-octylaluminumbis(dimethyl(t-butyl)siloxide, ethylzinc (2,6-diphenylphenoxide), andethylzinc (t-butoxide).

It will be appreciated by the skilled artisan that a suitable shuttlingagent for one catalyst or catalyst combination may not necessarily be asgood or even satisfactory for use with a different catalyst or catalystcombination. Some potential shuttling agents may adversely affect theperformance of one or more catalysts and may be undesirable for use forthat reason as well. Accordingly, the activity of the chain shuttlingagent desirably is balanced with the catalytic activity of the catalyststo achieve the desired polymer properties. In some embodiments of theinvention, best results may be obtained by use of shuttling agentshaving a chain shuttling activity (as measured by a rate of chaintransfer) that is less than the maximum possible rate.

Generally however, preferred shuttling agents possess the highest ratesof polymer transfer as well as the highest transfer efficiencies(reduced incidences of chain termination). Such shuttling agents may beused in reduced concentrations and still achieve the desired degree ofshuttling. In addition, such shuttling agents result in production ofthe shortest possible polymer block lengths. Highly desirably, chainshuttling agents with a single exchange site are employed due to thefact that the effective molecular weight of the polymer in the reactoris lowered, thereby reducing viscosity of the reaction mixture andconsequently reducing operating costs.

Catalysts

Suitable catalysts for use herein include any compound or combination ofcompounds that is adapted for preparing polymers of the desiredcomposition or type. Both heterogeneous and homogeneous catalysts may beemployed. Examples of heterogeneous catalysts include the well knownZiegler-Natta compositions, especially Group 4 metal halides supportedon Group 2 metal halides or mixed halides and alkoxides and the wellknown chromium or vanadium based catalysts. Preferably however, for easeof use and for production of narrow molecular weight polymer segments insolution, the catalysts for use herein are homogeneous catalystscomprising a relatively pure organometallic compound or metal complex,especially compounds or complexes based on metals selected from Groups3-10 or the Lanthanide series of the Periodic Table of the Elements. Itis preferred that any catalyst employed herein, not significantlydetrimentally affect the performance of the other catalyst under theconditions of the present polymerization. Desirably, no catalyst isreduced in activity by greater than 25 percent, more preferably greaterthan 10 percent under the conditions of the present polymerization.

Metal complexes for use herein having high tactic polymer formation(Catalyst A) include complexes of transition metals selected from Groups3 to 15 of the Periodic Table of the Elements containing one or moredelocalized, π-bonded ligands or polyvalent Lewis base ligands. Examplesinclude metallocene, half-metallocene, constrained geometry, andpolyvalent pyridylamine, or other polychelating base complexes. Thecomplexes are generically depicted by the formula: MK_(k)X_(x)Z_(z), ora dimer thereof, wherein

M is a metal selected from Groups 3-15, preferably 3-10, more preferably4-8, and most preferably Group 4 of the Periodic Table of the Elements;

K independently each occurrence is a group containing delocalizedπ-electrons or one or more electron pairs through which K is bound to M,said K group containing up to 50 atoms not counting hydrogen atoms,optionally two or more K groups may be joined together forming a bridgedstructure, and further optionally one or more K groups may be bound toZ, to X or to both Z and X;

X independently each occurrence is a monovalent, anionic moiety havingup to 40 non-hydrogen atoms, optionally one or more X groups may bebonded together thereby forming a divalent or polyvalent anionic group,and, further optionally, one or more X groups and one or more Z groupsmay be bonded together thereby forming a moiety that is both covalentlybound to M and coordinated thereto;

Z independently each occurrence is a neutral, Lewis base donor ligand ofup to 50 non-hydrogen atoms containing at least one unshared electronpair through which Z is coordinated to M;

k is an integer from 0 to 3;

x is an integer from 1 to 4;

z is a number from 0 to 3; and

the sum, k+x, is equal to the formal oxidation state of M.

Suitable metal complexes include those containing from 1 to 3 π-bondedanionic or neutral ligand groups, which may be cyclic or non-cyclicdelocalized π-bonded anionic ligand groups. Exemplary of such π-bondedgroups are conjugated or nonconjugated, cyclic or non-cyclic diene anddienyl groups, allyl groups, boratabenzene groups, phosphole, and arenegroups. By the term” α-bonded” is meant that the ligand group is bondedto the transition metal by a sharing of electrons from a partiallydelocalized π-bond.

Each atom in the delocalized 1-bonded group may independently besubstituted with a radical selected from the group consisting ofhydrogen, halogen, hydrocarbyl, halohydrocarbyl, hydrocarbyl-substitutedheteroatoms wherein the heteroatom is selected from Group 14-16 of thePeriodic Table of the Elements, and such hydrocarbyl-substitutedheteroatom radicals further substituted with a Group 15 or 16 heteroatom containing moiety. In addition two or more such radicals maytogether form a fused ring system, including partially or fullyhydrogenated fused ring systems, or they may form a metallocycle withthe metal. Included within the term “hydrocarbyl” are C₁₋₂₀ straight,branched and cyclic alkyl radicals, C₆₋₂₀ aromatic radicals, C₇₋₂₀alkyl-substituted aromatic radicals, and C₇₋₂₀ aryl-substituted alkylradicals. Suitable hydrocarbyl-substituted heteroatom radicals includemono-, di- and tri-substituted radicals of boron, silicon, germanium,nitrogen, phosphorus or oxygen wherein each of the hydrocarbyl groupscontains from 1 to 20 carbon atoms. Examples include N,N-dimethylamino,pyrrolidinyl, trimethylsilyl, triethylsilyl, t-butyldimethylsilyl,methyldi(t-butyl)silyl, triphenylgermyl, and trimethylgermyl groups.Examples of Group 15 or 16 hetero atom containing moieties includeamino, phosphino, alkoxy, or alkylthio moieties or divalent derivativesthereof, for example, amide, phosphide, alkyleneoxy or alkylenethiogroups bonded to the transition metal or Lanthanide metal, and bonded tothe hydrocarbyl group, π-bonded group, or hydrocarbyl-substitutedheteroatom.

Examples of suitable anionic, delocalized π-bonded groups includecyclopentadienyl, indenyl, fluorenyl, tetrahydroindenyl,tetrahydrofluorenyl, octahydrofluorenyl, pentadienyl, cyclohexadienyl,dihydroanthracenyl, hexahydroanthracenyl, decahydroanthracenyl groups,phosphole, and boratabenzyl groups, as well as inertly substitutedderivatives thereof, especially C₁₋₁₀ hydrocarbyl-substituted ortris(C₁₋₁₀ hydrocarbyl)silyl-substituted derivatives thereof. Preferredanionic delocalized π-bonded groups are cyclopentadienyl,pentamethylcyclopentadienyl, tetramethylcyclopentadienyl,tetramethylsilylcyclopentadienyl, indenyl, 2,3-dimethylindenyl,fluorenyl, 2-methylindenyl, 2-methyl-4-phenylindenyl,tetrahydrofluorenyl, octahydrofluorenyl, 1-indacenyl,3-pyrrolidinoinden-1-yl, 3,4-(cyclopenta(1)phenanthren-1-yl, andtetrahydroindenyl.

The boratabenzenyl ligands are anionic ligands which are boroncontaining analogues to benzene. They are previously known in the arthaving been described by G. Herberich, et al., in Organometallics, 14,1, 471-480 (1995). Preferred boratabenzenyl ligands correspond to theformula:

wherein R¹ is an inert substituent, preferably selected from the groupconsisting of hydrogen, hydrocarbyl, silyl, halo or germyl, said R¹having up to 20 atoms not counting hydrogen, and optionally two adjacentR¹ groups may be joined together. In complexes involving divalentderivatives of such delocalized π-bonded groups one atom thereof isbonded by means of a covalent bond or a covalently bonded divalent groupto another atom of the complex thereby forming a bridged system.

Phospholes are anionic ligands that are phosphorus containing analoguesto a cyclopentadienyl group. They are previously known in the art havingbeen described by WO 98/50392, and elsewhere. Preferred phospholeligands correspond to the formula:

wherein R¹ is as previously defined.

Preferred transition metal complexes for use herein correspond to theformula: MK_(k)X_(x)Z_(z), or a dimer thereof, wherein:

M is a Group 4 metal;

K is a group containing delocalized π-electrons through which K is boundto M, said K group containing up to 50 atoms not counting hydrogenatoms, optionally two K groups may be joined together forming a bridgedstructure, and further optionally one K may be bound to X or Z;

X each occurrence is a monovalent, anionic moiety having up to 40non-hydrogen atoms, optionally one or more X and one or more K groupsare bonded together to form a metallocycle, and further optionally oneor more X and one or more Z groups are bonded together thereby forming amoiety that is both covalently bound to M and coordinated thereto;

Z independently each occurrence is a neutral, Lewis base donor ligand ofup to 50 non-hydrogen atoms containing at least one unshared electronpair through which Z is coordinated to M;

k is an integer from 0 to 3;

x is an integer from 1 to 4;

z is a number from 0 to 3; and

the sum, k+x, is equal to the formal oxidation state of M.

Preferred complexes include those containing either one or two K groups.The latter complexes include those containing a bridging group linkingthe two K groups. Preferred bridging groups are those corresponding tothe formula (ER′₂)_(c) wherein E is silicon, germanium, tin, or carbon,R′ independently each occurrence is hydrogen or a group selected fromsilyl, hydrocarbyl, hydrocarbyloxy and combinations thereof, said R′having up to 30 carbon or silicon atoms, and e is 1 to 8. Preferably, R′independently each occurrence is methyl, ethyl, propyl, benzyl,tert-butyl, phenyl, methoxy, ethoxy or phenoxy.

Examples of the complexes containing two K groups are compoundscorresponding to the formula:

wherein:

M is titanium, zirconium or hafnium, preferably zirconium or hafnium, inthe +2 or +4 formal oxidation state;

R³ in each occurrence independently is selected from the groupconsisting of hydrogen, hydrocarbyl, silyl, germyl, cyano, halo andcombinations thereof, said R³ having up to 20 non-hydrogen atoms, oradjacent R³ groups together form a divalent derivative (that is, ahydrocarbadiyl, siladiyl or germadiyl group) thereby forming a fusedring system, and

X″ independently each occurrence is an anionic ligand group of up to 40non-hydrogen atoms, or two X″ groups together form a divalent anionicligand group of up to 40 non-hydrogen atoms or together are a conjugateddiene having from 4 to 30 non-hydrogen atoms bound by means ofdelocalized π-electrons to M, whereupon M is in the +2 formal oxidationstate, and

R′, E and e are as previously defined.

Exemplary bridged ligands containing two π-bonded groups are:dimethylbis(cyclopentadienyl)silane,dimethylbis(tetramethylcyclopentadienyl)silane,dimethylbis(2-ethylcyclopentadien-1-yl)silane,dimethylbis(2-t-butylcyclopentadien-1-yl)silane,2,2-bis(tetramethylcyclopentadienyl)propane,dimethylbis(inden-1-yl)silane, dimethylbis(tetrahydroinden-1-yl)silane,dimethylbis(fluoren-1-yl)silane,dimethylbis(tetrahydrofluoren-1-yl)silane,dimethylbis(2-methyl-4-phenylinden-1-yl)-silane,dimethylbis(2-methylinden-1-yl)silane,dimethyl(cyclopentadienyl)(fluoren-1-yl)silane,dimethyl(cyclopentadienyl)(octahydrofluoren-1-yl)silane,dimethyl(cyclopentadienyl)(tetrahydrofluoren-1-yl)silane,(1,1,2,2-tetramethyl)-1,2-bis(cyclopentadienyl)disilane,(1,2-bis(cyclopentadienyl)ethane, anddimethyl(cyclopentadienyl)-1-(fluoren-1-yl)methane.

Preferred X″ groups are selected from hydride, hydrocarbyl, silyl,germyl, halohydrocarbyl, halosilyl, silylhydrocarbyl andaminohydrocarbyl groups, or two X″ groups together form a divalentderivative of a conjugated diene or else together they form a neutral,π-bonded, conjugated diene. Most preferred X″ groups are C₁₋₂₀hydrocarbyl groups.

Examples of metal complexes of the foregoing formula suitable for use inthe present invention include:

-   bis(cyclopentadienyl)zirconiumdimethyl,-   bis(cyclopentadienyl)zirconium dibenzyl,-   bis(cyclopentadienyl)zirconium methyl benzyl,-   bis(cyclopentadienyl)zirconium methyl phenyl,-   bis(cyclopentadienyl)zirconiumdiphenyl,-   bis(cyclopentadienyl)titanium-allyl,-   bis(cyclopentadienyl)zirconiummethylmethoxide,-   bis(cyclopentadienyl)zirconiummethylchloride,-   bis(pentamethylcyclopentadienyl)zirconiumdimethyl,-   bis(pentamethylcyclopentadienyl)titaniumdimethyl,-   bis(indenyl)zirconiumdimethyl,-   indenylfluorenylzirconiumdimethyl,-   bis(indenyl)zirconiummethyl(2-(dimethylamino)benzyl),-   bis(indenyl)zirconiummethyltrimethylsilyl,-   bis(tetrahydroindenyl)zirconiummethyltrimethylsilyl,-   bis(pentamethylcyclopentadienyl)zirconiummethylbenzyl,-   bis(pentamethylcyclopentadienyl)zirconiumdibenzyl,-   bis(pentamethylcyclopentadienyl)zirconiummethylmethoxide,-   bis(pentamethylcyclopentadienyl)zirconiummethylchloride,-   bis(methylethylcyclopentadienyl)zirconiumdimethyl,-   bis(butylcyclopentadienyl)zirconiumdibenzyl,-   bis(t-butylcyclopentadienyl)zirconiumdimethyl,-   bis(ethyltetramethylcyclopentadienyl)zirconiumdimethyl,-   bis(methylpropylcyclopentadienyl)zirconiumdibenzyl,-   bis(trimethylsilylcyclopentadienyl)zirconiumdibenzyl,-   dimethylsilylbis(cyclopentadienyl)zirconiumdichloride,-   dimethylsilylbis(cyclopentadienyl)zirconiumdimethyl,-   dimethylsilylbis(tetramethylcyclopentadienyl)titanium (III) allyl-   dimethylsilylbis(t-butylcyclopentadienyl)zirconiumdichloride,-   dimethylsilylbis(n-butylcyclopentadienyl)zirconiumdichloride,-   (dimethylsilylbis(tetramethylcyclopentadienyl)titanium(III)    2-(dimethylamino)benzyl,-   (dimethylsilylbis(n-butylcyclopentadienyl)titanium(III)    2-(dimethylamino)benzyl,-   dimethylsilylbis(indenyl)zirconiumdichloride,-   dimethylsilylbis(indenyl)zirconiumdimethyl,-   dimethylsilylbis(2-methylindenyl)zirconiumdimethyl,-   dimethylsilylbis(2-methyl-4-phenylindenyl)zirconiumdimethyl,-   dimethylsilylbis(2-methylindenyl)zirconium-1,4-diphenyl-1,3-butadiene,-   dimethylsilylbis(2-methyl-4-phenylindenyl)zirconium (II)    1,4-diphenyl-1,3-butadiene,-   dimethylsilylbis(4,5,6,7-tetrahydroinden-1-yl)zirconiumdichloride,-   dimethylsilylbis(4,5,6,7-tetrahydroinden-1-yl)zirconiumdimethyl,-   dimethylsilylbis(tetrahydroindenyl)zirconium(II)    1,4-diphenyl-1,3-butadiene,-   dimethylsilylbis(tetramethylcyclopentadienyl)zirconium dimethyl-   dimethylsilylbis(fluorenyl)zirconiumdimethyl,-   dimethylsilylbis(tetrahydrofluorenyl)zirconium bis(trimethylsilyl),-   ethylenebis(indenyl)zirconiumdichloride,-   ethylenebis(indenyl)zirconiumdimethyl,-   ethylenebis(4,5,6,7-tetrahydroindenyl)zirconiumdichloride,-   ethylenebis(4,5,6,7-tetrahydroindenyl)zirconiumdimethyl,-   (isopropylidene)(cyclopentadienyl)(fluorenyl)zirconiumdibenzyl, and-   dimethylsilyl(tetramethylcyclopentadienyl)(fluorenyl)zirconium    dimethyl.

A further class of metal complexes utilized in the present inventioncorresponds to the preceding formula: MKZ_(z)X_(x), or a dimer thereof,wherein M, K, X, x and z are as previously defined, and Z is asubstituent of up to 50 non-hydrogen atoms that together with K forms ametallocycle with M.

Preferred Z substituents include groups containing up to 30 non-hydrogenatoms comprising at least one atom that is oxygen, sulfur, boron or amember of Group 14 of the Periodic Table of the Elements directlyattached to K, and a different atom, selected from the group consistingof nitrogen, phosphorus, oxygen or sulfur that is covalently bonded toM.

More specifically this class of Group 4 metal complexes used accordingto the present invention includes “constrained geometry catalysts”corresponding to the formula:

wherein:

M is titanium or zirconium, preferably titanium in the +2, +3, or +4formal oxidation state;

K¹ is a delocalized, 7-bonded ligand group optionally substituted withfrom 1 to 5 R² groups,

R² in each occurrence independently is selected from the groupconsisting of hydrogen, hydrocarbyl, silyl, germyl, cyano, halo andcombinations thereof, said R² having up to 20 non-hydrogen atoms, oradjacent R² groups together form a divalent derivative (that is, ahydrocarbadiyl, siladiyl or germadiyl group) thereby forming a fusedring system,

each X is a halo, hydrocarbyl, hydrocarbyloxy or silyl group, said grouphaving up to 20 non-hydrogen atoms, or two X groups together form aneutral C₅₋₃₀ conjugated diene or a divalent derivative thereof;

x is 1 or 2;

Y is —O—, —S—, —NR′—, —PR′—; and

X′ is SiR′₂, CR′₂, SiR′₂SiR′₂, CR′₂CR′₂, CR′═CR′, CR′₂SiR′₂, or GeR′₂,wherein

R′ independently each occurrence is hydrogen or a group selected fromsilyl, hydrocarbyl, hydrocarbyloxy and combinations thereof, said R′having up to 30 carbon or silicon atoms.

Specific examples of the foregoing constrained geometry metal complexesinclude compounds corresponding to the formula:

wherein,

Ar is an aryl group of from 6 to 30 atoms not counting hydrogen;

R⁴ independently each occurrence is hydrogen, Ar, or a group other thanAr selected from hydrocarbyl, trihydrocarbylsilyl, trihydrocarbylgermyl,halide, hydrocarbyloxy, trihydrocarbylsiloxy,bis(trihydrocarbylsilyl)amino, di(hydrocarbyl)amino,hydrocarbadiylamino, hydrocarbylimino, di(hydrocarbyl)phosphino,hydrocarbadiylphosphino, lydrocarbylsulfido, halo-substitutedhydrocarbyl, hydrocarbyloxy-substituted hydrocarbyl,trihydrocarbylsilyl-substituted hydrocarbyl,trihydrocarbylsiloxy-substituted hydrocarbyl,bis(trihydrocarbylsilyl)amino-substituted hydrocarbyl,di(hydrocarbyl)amino-substituted hydrocarbyl,hydrocarbyleneamino-substituted hydrocarbyl,di(hydrocarbyl)phosphino-substituted hydrocarbyl,hydrocarbylenephosphino-substituted hydrocarbyl, orhydrocarbylsulfido-substituted hydrocarbyl, said R group having up to 40atoms not counting hydrogen atoms, and optionally two adjacent R⁴ groupsmay be joined together forming a polycyclic fused ring group;

M is titanium;

X′ is SiR⁶ ₂, CR⁶ ₂, SiR⁶ ₂SiR⁶ ₂, CR⁶ ₂CR⁶ ₂, CR⁶═CR⁶, CR⁶ ₂SiR⁶ ₂,BR⁶, BR⁶L″, or GeR⁶ ₂;

Y is —O—, —S—, —NR⁵—, —PR⁵—; —NR⁵ ₂, or —PR⁵ ₂;

R⁵, independently each occurrence, is hydrocarbyl, trihydrocarbylsilyl,or trihydrocarbylsilylhydrocarbyl, said R⁵ having up to 20 atoms otherthan hydrogen, and optionally two R⁵ groups or R⁵ together with Y or Zform a ring system;

R⁶, independently each occurrence, is hydrogen, or a member selectedfrom hydrocarbyl, hydrocarbyloxy, silyl, halogenated alkyl, halogenatedaryl, —NR⁵ ₂, and combinations thereof, said R⁶ having up to 20non-hydrogen atoms, and optionally, two R⁶ groups or R⁶ together with Zforms a ring system;

Z is a neutral diene or a monodentate or polydentate Lewis baseoptionally bonded to R⁵, R⁶, or X;

X is hydrogen, a monovalent anionic ligand group having up to 60 atomsnot counting hydrogen, or two X groups are joined together therebyforming a divalent ligand group;

x is 1 or 2; and

z is 0, 1 or 2.

Preferred examples of the foregoing metal complexes are substituted atboth the 3- and 4-positions of a cyclopentadienyl or indenyl group withan Ar group.

Examples of the foregoing metal complexes include:

-   (3-phenylcyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dichloride,-   (3-phenylcyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dimethyl,-   (3-phenylcyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium (II)    1,3-diphenyl-1,3-butadiene;-   (3-(pyrrol-1-yl)cyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dichloride,-   (3-(pyrrol-1-yl)cyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dimethyl,-   (3-(pyrrol-1-yl)cyclopentadien-1-yl))dimethyl(t-butylamido)silanetitanium (11)    1,4-diphenyl-1,3-butadiene;-   (3-(1-methylpyrrol-3-yl)cyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dichloride,-   (3-(1-methylpyrrol-3-yl)cyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dimethyl,-   (3-(1-methylpyrrol-3-yl)cyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium (II)    1,4-diphenyl-1,3-butadiene;-   (3,4-diphenylcyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dichloride,-   (3,4-diphenylcyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dimethyl,-   (3,4-diphenylcyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium (II)    1,3-pentadiene;-   (3-(3-N,N-dimethylamino)phenyl)cyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dichloride,-   (3-(3-N,N-dimethylamino)phenylcyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dimethyl,-   (3-(3-N,N-dimethylamino)phenylcyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium (II)    1,4-diphenyl-1,3-butadiene;-   (3-(4-methoxyphenyl)-4-methylcyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dichloride,-   (3-(4-methoxyphenyl)-4-phenylcyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dimethyl,-   (3-4-methoxyphenyl)-4-phenylcyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium (II)    1,4-diphenyl-1,3-butadiene;-   (3-phenyl-4-methoxycyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dichloride,-   (3-phenyl-4-methoxycyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dimethyl,    (3-phenyl-4-methoxycyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium (1)    1,4-diphenyl-1,3-butadiene;-   (3-phenyl-4-(N,N-dimethylamino)cyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dichloride,-   (3-phenyl-4-(N,N-dimethylamino)cyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dimethyl,-   (3-phenyl-4-(N,N-dimethylamino)cyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium (II)    1,4-diphenyl-1,3-butadiene;-   2-methyl-(3,4-di(4-methylphenyl)cyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dichloride,-   2-methyl-(3,4-di(4-methylphenyl)cyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dimethyl,-   2-methyl-(3,4-di(4-methylphenyl)cyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium (II)    1,4-diphenyl-1,3-butadiene;-   ((2,3-diphenyl)-4-(N,N-dimethylamino)cyclopentadien-1-yl)dimethyl(t-butylamido)silane    titanium dichloride,-   ((2,3-diphenyl)-4-(N,N-dimethylamino)cyclopentadien-1-yl)dimethyl(t-butylamido)silane    titanium dimethyl,-   ((2,3-diphenyl)-4-(N,N-dimethylamino)cyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium (II)    1,4-diphenyl-1,3-butadiene;-   (2,3,4-triphenyl-5-methylcyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dichloride,-   (2,3,4-triphenyl-5-methylcyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dimethyl,-   (2,3,4-triphenyl-5-methylcyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium (II)    1,4-diphenyl-1,3-butadiene;-   (3-phenyl-4-methoxycyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dichloride,-   (3-phenyl-4-methoxycyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dimethyl,-   (3-phenyl-4-methoxycyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium (1)    1,4-diphenyl-1,3-butadiene;-   (2,3-diphenyl-4-(n-butyl)cyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dichloride,-   (2,3-diphenyl-4-(n-butyl)cyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dimethyl,-   (2,3-diphenyl-4-(n-butyl)cyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium (II)    1,4-diphenyl-1,3-butadiene;-   (2,3,4,5-tetraphenylcyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dichloride,-   (2,3,4,5-tetraphenylcyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dimethyl, and-   (2,3,4,5-tetraphenylcyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium (1)    1,4-diphenyl-1,3-butadiene.

Additional examples of suitable metal complexes for use as catalyst (A)herein are polycyclic complexes corresponding to the formula:

where M is titanium in the +2, +3 or +4 formal oxidation state;

R⁷ independently each occurrence is hydride, hydrocarbyl, silyl, germyl,halide, hydrocarbyloxy, hydrocarbylsiloxy, hydrocarbylsilylamino,di(hydrocarbyl)amino, hydrocarbyleneamino, di(hydrocarbyl)phosphino,hydrocarbylene-phosphino, hydrocarbylsulfido, halo-substitutedhydrocarbyl, hydrocarbyloxy-substituted hydrocarbyl, silyl-substitutedhydrocarbyl, hydrocarbylsiloxy-substituted hydrocarbyl,hydrocarbylsilylamino-substituted hydrocarbyl,di(hydrocarbyl)amino-substituted hydrocarbyl,hydrocarbyleneamino-substituted hydrocarbyl,di(hydrocarbyl)phosphino-substituted hydrocarbyl,hydrocarbylene-phosphino-substituted hydrocarbyl, orhydrocarbylsulfido-substituted hydrocarbyl, said R⁷ group having up to40 atoms not counting hydrogen, and optionally two or more of theforegoing groups may together form a divalent derivative;

R⁸ is a divalent hydrocarbylene- or substituted hydrocarbylene groupforming a fused system with the remainder of the metal complex, said R⁸containing from 1 to 30 atoms not counting hydrogen;

X^(a) is a divalent moiety, or a moiety comprising one α-bond and aneutral two electron pair able to form a coordinate-covalent bond to M,said X^(a) comprising boron, or a member of Group 14 of the PeriodicTable of the Elements, and also comprising nitrogen, phosphorus, sulfuror oxygen;

X is a monovalent anionic ligand group having up to 60 atoms exclusiveof the class of ligands that are cyclic, delocalized, π-bound ligandgroups and optionally two X groups together form a divalent ligandgroup;

Z independently each occurrence is a neutral ligating compound having upto 20 atoms;

x is 0, 1 or 2; and

z is zero or 1.

Preferred examples of such complexes are 3-phenyl-substituteds-indecenyl complexes corresponding to the formula:

2,3-dimethyl-substituted s-indecenyl complexes corresponding to theformulas:

or 2-methyl-substituted s-indecenyl complexes corresponding to theformula:

Additional examples of metal complexes that are usefully employed ascatalyst (A) according to the present invention include those of theformula:

Specific metal complexes include:

-   (8-methylene-1,8-dihydrodibenzo[e,h]azulen-1-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (II) 1,4-diphenyl-1,3-butadiene,-   (8-methylene-1,8-dihydrodibenzo[e,h]azulen-1-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (II) 1,3-pentadiene,-   (8-methylene-1,8-dihydrodibenzo[e,h]azulen-1-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (III) 2-(N,N-dimethylamino)benzyl,-   (8-methylene-1,8-dihydrodibenzo[e,h]azulen-1-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (IV) dichloride,-   (8-methylene-1,8-dihydrodibenzo[e,h]azulen-1-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (IV) dimethyl,-   (8-methylene-1,8-dihydrodibenzo[e,h]azulen-1-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (IV) dibenzyl,-   (8-difluoromethylene-1,8-dihydrodibenzo[e,h]azulen-1-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (II) 1,4-diphenyl-1,3-butadiene,-   (8-difluoromethylene-1,8-dihydrodibenzo[e,h]azulen-1-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (II) 1,3-pentadiene,-   (8-difluoromethylene-1,8-dihydrodibenzo[e,h]azulen-1-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (III) 2-(N,N-dimethylamino)benzyl,-   (8-difluoromethylene-1,8-dihydrodibenzo[e,h]azulen-1-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (IV) dichloride,-   (8-difluoromethylene-1,8-dihydrodibenzo[e,h]azulen-1-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (IV) dimethyl,-   (8-difluoromethylene-1,8-dihydrodibenzo[e,h]azulen-1-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (IV) dibenzyl,-   (8-methylene-1,8-dihydrodibenzo[e,h]azulen-2-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (II) 1,4-diphenyl-1,3-butadiene,-   (8-methylene-1,8-dihydrodibenzo[e,h]azulen-2-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (II) 1,3-pentadiene,-   (8-methylene-1,8-dihydrodibenzo[e,h]azulen-2-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (III) 2-(N,N-dimethylamino)benzyl,-   (8-methylene-1,8-dihydrodibenzo[e,h]azulen-2-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (IV) dichloride,-   (8-methylene-1,8-dihydrodibenzo[e,h]azulen-2-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (IV) dimethyl,-   (8-methylene-1,8-dihydrodibenzo[e,h]azulen-2-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (IV) dibenzyl,-   (8-difluoromethylene-1,8-dihydrodibenzo[e,h]azulen-2-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (II) 1,4-diphenyl-1,3-butadiene,-   (8-difluoromethylene-1,8-dihydrodibenzo[e,h]azulen-2-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (II) 1,3-pentadiene,-   (8-difluoromethylene-1,8-dihydrodibenzo[e,h]azulen-2-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (III) 2-(N,N-dimethylamino)benzyl,-   (8-difluoromethylene-1,8-dihydrodibenzo[e,h]azulen-2-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (IV) dichloride,-   (8-difluoromethylene-1,8-dihydrodibenzo[e,h]azulen-2-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (IV) dimethyl,-   (8-difluoromethylene-1,8-dihydrodibenzo[e,h]azulen-2-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (IV) dibenzyl, and mixtures thereof, especially mixtures of    positional isomers.

Further illustrative examples of metal complexes for use according tothe present invention correspond to the formula:

where M is titanium in the +2, +3 or +4 formal oxidation state;

T is —NR⁹— or —O—;

R⁹ is hydrocarbyl, silyl, germyl, dihydrocarbylboryl, or halohydrocarbylor up to 10 atoms not counting hydrogen;

R¹⁰ independently each occurrence is hydrogen, hydrocarbyl,trihydrocarbylsilyl, trihydrocarbylsilylhydrocarbyl, germyl, halide,hydrocarbyloxy, hydrocarbylsiloxy, hydrocarbylsilylamino,di(hydrocarbyl)amino, hydrocarbyleneamino, di(hydrocarbyl)phosphino,hydrocarbylene-phosphino, hydrocarbylsulfido, halo-substitutedhydrocarbyl, hydrocarbyloxy-substituted hydrocarbyl, silyl-substitutedhydrocarbyl, hydrocarbylsiloxy-substituted hydrocarbyl,hydrocarbylsilylamino-substituted hydrocarbyl,di(hydrocarbyl)amino-substituted hydrocarbyl,hydrocarbyleneamino-substituted hydrocarbyl,di(hydrocarbyl)phosphino-substituted hydrocarbyl,hydrocarbylenephosphino-substituted hydrocarbyl, orhydrocarbylsulfido-substituted hydrocarbyl, said R¹⁰ group having up to40 atoms not counting hydrogen atoms, and optionally two or more of theforegoing adjacent R¹⁰ groups may together form a divalent derivativethereby forming a saturated or unsaturated fused ring;

X^(a) is a divalent moiety lacking in delocalized π-electrons, or such amoiety comprising one π-bond and a neutral two electron pair able toform a coordinate-covalent bond to M, said X′ comprising boron, or amember of Group 14 of the Periodic Table of the Elements, and alsocomprising nitrogen, phosphorus, sulfur or oxygen;

X is a monovalent anionic ligand group having up to 60 atoms exclusiveof the class of ligands that are cyclic ligand groups bound to M throughdelocalized π-electrons or two X groups together are a divalent anionicligand group;

Z independently each occurrence is a neutral ligating compound having upto 20 atoms;

x is 0, 1, 2, or 3; and

z is 0 or 1.

Highly preferably T is ═N(CH₃), X is halo or hydrocarbyl, x is 2, X′ isdimethylsilane, z is 0, and R¹⁰ each occurrence is hydrogen, ahydrocarbyl, hydrocarbyloxy, dihydrocarbylamino, hydrocarbyleneamino,dihydrocarbylamino-substituted hydrocarbyl group, orhydrocarbyleneamino-substituted hydrocarbyl group of up to 20 atoms notcounting hydrogen, and optionally two R¹⁰ groups may be joined together.

Illustrative metal complexes of the foregoing formula that may beemployed in the practice of the present invention further include thefollowing compounds:

-   (t-butylamido)dimethyl-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (II)    1,4-diphenyl-1,3-butadiene,-   (t-butylamido)dimethyl-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (II)    1,3-pentadiene,-   (t-butylamido)dimethyl-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (III)    2-(N,N-dimethylamino)benzyl,-   (t-butylamido)dimethyl-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (IV)    dichloride,-   (t-butylamido)dimethyl-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (IV)    dimethyl,-   (t-butylamido)dimethyl-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (IV)    dibenzyl,-   (t-butylamido)dimethyl-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (IV)    bis(trimethylsilyl),-   (cyclohexylamido)dimethyl-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (II)    1,4-diphenyl-1,3-butadiene,-   (cyclohexylamido)dimethyl-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (II)    1,3-pentadiene,-   (cyclohexylamido)dimethyl-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (III)    2-(N,N-dimethylamino)benzyl,-   (cyclohexylamido)dimethyl-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (IV)    dichloride,-   (cyclohexylamido)dimethyl-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (IV)    dimethyl,-   (cyclohexylamido)dimethyl-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (IV)    dibenzyl,-   (cyclohexylamido)dimethyl-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (IV)    bis(trimethylsilyl),-   (t-butylamido)di(p-methylphenyl)-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (II)    1,4-diphenyl-1,3-butadiene,-   (t-butylamido)di(p-methylphenyl)-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (II)    1,3-pentadiene,-   (t-butylamido)di(p-methylphenyl)-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (II)    2-(N,N-dimethylamino)benzyl,-   (t-butylamido)di(p-methylphenyl)-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (IV)    dichloride,-   (t-butylamido)di(p-methylphenyl)-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (IV)    dimethyl,-   (t-butylamido)di(p-methylphenyl)-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (IV)    dibenzyl,-   (t-butylamido)di(p-methylphenyl)-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (IV)    bis(trimethylsilyl),-   (cyclohexylamido)di(p-methylphenyl)-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (II)    1,4-diphenyl-1,3-butadiene,-   (cyclohexylamido)di(p-methylphenyl)-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (II)    1,3-pentadiene,-   (cyclohexylamido)di(p-methylphenyl)-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (III)    2-(N,N-dimethylamino)benzyl,-   (cyclohexylamido)di(p-methylphenyl)-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (IV)    dichloride,-   (cyclohexylamido)di(p-methylphenyl)-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (IV)    dimethyl,-   (cyclohexylamido)di(p-methylphenyl)-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (IV)    dibenzyl; and-   (cyclohexylamido)di(p-methylphenyl)-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (IV)    bis(trimethylsilyl).

Illustrative Group 4 metal complexes that may be employed in thepractice of the present invention further include:

-   (tert-butylamido)(1,1-dimethyl-2,3,4,9,10-η-1,4,5,6,7,8-hexahydronaphthalenyl)dimethylsilanetitaniumdimethyl,-   (tert-butylamido)(1,1,2,3-tetramethyl-2,3,4,9,10-η-1,4,5,6,7,8-hexahydronaphthalenyl)dimethylsilanetitaniumdimethyl,-   (tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethylsilanetitanium    dibenzyl,-   (tert-butylamido)(tetramethyl-5-cyclopentadienyl)dimethylsilanetitanium    dimethyl,    (tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)-1,2-ethanediyltitanium    dimethyl,-   (tert-butylamido)(tetramethyl-μ⁵-indenyl)dimethylsilanetitanium    dimethyl,-   (tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethylsilane    titanium (III) 2-(dimethylamino)benzyl;-   (tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethylsilanetitanium (III)    allyl,-   (tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethylsilanetitanium (III)    2,4-dimethylpentadienyl,-   (tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethylsilanetitanium (II)    1,4-diphenyl-1,3-butadiene,-   (tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethylsilanetitanium (II)    1,3-pentadiene,-   (tert-butylamido)(2-methylindenyl)dimethylsilanetitanium (II)    1,4-diphenyl-1,3-butadiene,-   (tert-butylamido)(2-methylindenyl)dimethylsilanetitanium (II)    2,4-hexadiene,-   (tert-butylamido)(2-methylindenyl)dimethylsilanetitanium (IV)    2,3-dimethyl-1,3-butadiene,-   (tert-butylamido)(2-methylindenyl)dimethylsilanetitanium (IV)    isoprene,-   (tert-butylamido)(2-methylindenyl)dimethylsilanetitanium (IV)    1,3-butadiene,-   (tert-butylamido)(2,3-dimethylindenyl)dimethylsilanetitanium (IV)    2,3-dimethyl-1,3-butadiene,-   (tert-butylamido)(2,3-dimethylindenyl)dimethylsilanetitanium (IV)    isoprene-   (tert-butylamido)(2,3-dimethylindenyl)dimethylsilanetitanium (IV)    dimethyl-   (tert-butylamido)(2,3-dimethylindenyl)dimethylsilanetitanium (IV)    dibenzyl-   (tert-butylamido)(2,3-dimethylindenyl)dimethylsilanetitanium (IV)    1,3-butadiene,-   (tert-butylamido)(2,3-dimethylindenyl)dimethylsilanetitanium (II)    1,3-pentadiene,-   (tert-butylamido)(2,3-dimethylindenyl)dimethylsilanetitanium (II)    1,4-diphenyl-1,3-butadiene,-   (tert-butylamido)(2-methylindenyl)dimethylsilanetitanium (II)    1,3-pentadiene,-   (tert-butylamido)(2-methylindenyl)dimethylsilanetitanium (IV)    dimethyl,-   (tert-butylamido)(2-methylindenyl)dimethylsilanetitanium (IV)    dibenzyl,-   (tert-butylamido)(2-methyl-4-phenylindenyl)dimethylsilanetitanium (II)    1,4-diphenyl-1,3-butadiene,-   (tert-butylamido)(2-methyl-4-phenylindenyl)dimethylsilanetitanium (II)    1,3-pentadiene,-   (tert-butylamido)(2-methyl-4-phenylindenyl)dimethylsilanetitanium (II)    2,4-hexadiene,    (tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethyl-silanetitanium (IV)    1,3-butadiene,-   (tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethylsilanetitanium (IV)    2,3-dimethyl-1,3-butadiene,-   (tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethylsilanetitanium (IV)    isoprene,-   (tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethyl-silanetitanium (II)    1,4-dibenzyl-1,3-butadiene,-   (tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethylsilanetitanium (II)    2,4-hexadiene,-   (tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethyl-silanetitanium (II)    3-methyl-1,3-pentadiene,-   (tert-butylamido)(2,4-dimethylpentadien-3-yl)dimethylsilanetitaniumdimethyl,-   (tert-butylamido)(6,6-dimethylcyclohexadienyl)dimethylsilanetitaniumdimethyl,-   (tert-butylamido)(1,1-dimethyl-2,3,4,9,10-α-1,4,5,6,7,8-hexahydronaphthalen-4-yl)dimethylsilanetitaniumdimethyl,-   (tert-butylamido)(1,1,2,3-tetramethyl-2,3,4,9,10-η-1,4,5,6,7,8-hexahydronaphthalen-4-yl)dimethylsilanetitaniumdimethyl-   (tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl    methylphenylsilanetitanium (IV) dimethyl,-   (tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl    methylphenylsilanetitanium (II) 1,4-diphenyl-1,3-butadiene,-   1-(tert-butylamido)-2-(tetramethyl-η⁵-cyclopentadienyl)ethanediyltitanium (V)    dimethyl, and-   1-(tert-butylamido)-2-(tetramethyl-η⁵-cyclopentadienyl)ethanediyl-titanium (II)    1,4-diphenyl-1,3-butadiene.

Other delocalized, π-bonded complexes, especially those containing otherGroup 4 metals, will, of course, be apparent to those skilled in theart, and are disclosed among other places in: WO 03/78480, WO 03/78483,WO 02/92610, WO 02/02577, US 2003/0004286 and U.S. Pat. Nos. 6,515,155,6,555,634, 6,150,297, 6,034,022, 6,268,444, 6,015,868, 5,866,704, and5,470,993.

Additional examples of metal complexes that are usefully employed ascatalyst (A) are complexes of polyvalent Lewis bases, such as compoundscorresponding to the formula:

wherein T^(b) is a bridging group, preferably containing 2 or more atomsother than hydrogen,

X^(b) and Y^(b) are each independently selected from the groupconsisting of nitrogen, sulfur, oxygen and phosphorus; more preferablyboth X^(b) and Y^(b) are nitrogen,

R^(b) and R^(b)′ independently each occurrence are hydrogen or C₁₋₅₀hydrocarbyl groups optionally containing one or more heteroatoms orinertly substituted derivative thereof. Non-limiting examples ofsuitable R^(b) and R^(b)′ groups include alkyl, alkenyl, aryl, aralkyl,(poly)alkylaryl and cycloalkyl groups, as well as nitrogen, phosphorus,oxygen and halogen substituted derivatives thereof. Specific examples ofsuitable R^(b) and R^(b)′ groups include methyl, ethyl, isopropyl,octyl, phenyl, 2,6-dimethylphenyl, 2,6-di(isopropyl)phenyl,2,4,6-trimethylphenyl, pentafluorophenyl, 3,5-trifluoromethylphenyl, andbenzyl;

g is 0 or 1;

M^(b) is a metallic element selected from Groups 3 to 15, or theLanthanide series of the Periodic Table of the Elements. Preferably,M^(b) is a Group 3-13 metal, more preferably M^(b) is a Group 4-10metal;

L^(b) is a monovalent, divalent, or trivalent anionic ligand containingfrom 1 to 50 atoms, not counting hydrogen. Examples of suitable L^(b)groups include halide; hydride; hydrocarbyl, hydrocarbyloxy;di(hydrocarbyl)amido, hydrocarbyleneamido, di(hydrocarbyl)phosphido;hydrocarbylsulfido; hydrocarbyloxy, tri(hydrocarbylsilyl)alkyl; andcarboxylates. More preferred L^(b) groups are C₁₋₂₀ alkyl, C₇₋₂₀aralkyl, and chloride;

h is an integer from 1 to 6, preferably from 1 to 4, more preferablyfrom 1 to 3, and j is 1 or 2, with the value h×j selected to providecharge balance;

Z^(b) is a neutral ligand group coordinated to M^(b), and containing upto 50 atoms not counting hydrogen Preferred Z^(b) groups includealiphatic and aromatic amines, phosphines, and ethers, alkenes,alkadienes, and inertly substituted derivatives thereof. Suitable inertsubstituents include halogen, alkoxy, aryloxy, alkoxycarbonyl,aryloxycarbonyl, di(hydrocarbyl)amine, tri(hydrocarbyl)silyl, andnitrile groups. Preferred Z^(b) groups include triphenylphosphine,tetrahydrofuran, pyridine, and 1,4-diphenylbutadiene;

f is an integer from 1 to 3;

two or three of Tb, R^(b) and R^(b)′ may be joined together to form asingle or multiple ring structure;

h is an integer from 1 to 6, preferably from 1 to 4, more preferablyfrom 1 to 3;

indicates any form of electronic interaction, especially coordinate orcovalent bonds, including multiple bonds, arrows signify coordinatebonds, and dotted lines indicate optional double bonds.

In one embodiment, it is preferred that R^(b) have relatively low sterichindrance with respect to X^(b). In this embodiment, most preferredR^(b) groups are straight chain alkyl groups, straight chain alkenylgroups, branched chain alkyl groups wherein the closest branching pointis at least 3 atoms removed from X^(b), and halo, dihydrocarbylamino,alkoxy or trihydrocarbylsilyl substituted derivatives thereof. Highlypreferred R^(b) groups in this embodiment are C₁₋₈ straight chain alkylgroups.

At the same time, in this embodiment R^(b)′ preferably has relativelyhigh steric hindrance with respect to Y^(b). Non-limiting examples ofsuitable R^(b)′ groups for this embodiment include alkyl or alkenylgroups containing one or more secondary or tertiary carbon centers,cycloalkyl, aryl, alkaryl, aliphatic or aromatic heterocyclic groups,organic or inorganic oligomeric, polymeric or cyclic groups, and halo,dihydrocarbylamino, alkoxy or trihydrocarbylsilyl substitutedderivatives thereof. Preferred R^(b)′ groups in this embodiment containfrom 3 to 40, more preferably from 3 to 30, and most preferably from 4to 20 atoms not counting hydrogen and are branched or cyclic.

Examples of preferred T^(b) groups are structures corresponding to thefollowing formulas:

Each R^(d) is C₁₋₁₀ hydrocarbyl group, preferably methyl, ethyl,n-propyl, i-propyl, t-butyl, phenyl, 2,6-dimethylphenyl, benzyl, ortolyl. Each R^(e) is C₁₋₁₀ hydrocarbyl, preferably methyl, ethyl,n-propyl, i-propyl, t-butyl, phenyl, 2,6-dimethylphenyl, benzyl, ortolyl. In addition, two or more R^(d) or R^(e) groups, or mixtures of Rdand Re groups may together form a polyvalent derivative of a hydrocarbylgroup, such as, 1,4-butylene, 1,5-pentylene, or a multicyclic, fusedring, polyvalent hydrocarbyl- or heterohydrocarbyl-group, such asnaphthalene-1,8-diyl.

Preferred examples of the foregoing polyvalent Lewis base complexesinclude:

wherein R^(d)′ each occurrence is independently selected from the groupconsisting of hydrogen and C₁₋₅₀ hydrocarbyl groups optionallycontaining one or more heteroatoms, or inertly substituted derivativethereof, or further optionally, two adjacent R^(d)′ groups may togetherform a divalent bridging group;

d′ is 4;

M^(b)′ is a Group 4 metal, preferably titanium or hafnium, or a Group 10metal, preferably Ni or Pd;

L^(b)′ is a monovalent ligand of up to 50 atoms not counting hydrogen,preferably halide or hydrocarbyl, or two L^(b)′ groups together are adivalent or neutral ligand group, preferably a C₂₋₅₀ hydrocarbylene,hydrocarbadiyl or diene group.

The polyvalent Lewis base complexes for use in the present inventionespecially include Group 4 metal derivatives, especially hafniumderivatives of hydrocarbylamine substituted heteroaryl compoundscorresponding to the formula:

wherein:

R¹¹ is selected from alkyl, cycloalkyl, heteroalkyl, cycloheteroalkyl,aryl, and inertly substituted derivatives thereof containing from 1 to30 atoms not counting hydrogen or a divalent derivative thereof;

T¹ is a divalent bridging group of from 1 to 41 atoms other thanhydrogen, preferably 1 to 20 atoms other than hydrogen, and mostpreferably a mono- or di-C₁₋₂₀ hydrocarbyl substituted methylene orsilane group; and

R¹² is a C₅₋₂₀ heteroaryl group containing Lewis base functionality,especially a pyridin-2-yl- or substituted pyridin-2-yl group or adivalent derivative thereof;

M¹ is a Group 4 metal, preferably hafnium;

X¹ is an anionic, neutral or dianionic ligand group;

x′ is a number from 0 to 5 indicating the number of such X¹ groups; and

bonds, optional bonds and electron donative interactions are representedby lines, dotted lines and arrows respectively.

Preferred complexes are those wherein ligand formation results fromhydrogen elimination from the amine group and optionally from the lossof one or more additional groups, especially from R². In addition,electron donation from the Lewis base functionality, preferably anelectron pair, provides additional stability to the metal center.Preferred metal complexes correspond to the formula:

M¹, X¹, x′, R¹¹ and T¹ are as previously defined,

R¹³, R¹⁴, R¹⁵ and R¹⁶ are hydrogen, halo, or an alkyl, cycloalkyl,heteroalkyl, heterocycloalkyl, aryl, or silyl group of up to 20 atomsnot counting hydrogen, or adjacent R³, R¹⁴, R¹⁵ or R¹⁶ groups may bejoined together thereby forming fused ring derivatives, and

bonds, optional bonds and electron pair donative interactions arerepresented by lines, dotted lines and arrows respectively.

More preferred examples of the foregoing metal complexes correspond tothe formula:

M¹, X¹, and x′ are as previously defined,

R¹³, R¹⁴, R¹⁵ and R¹⁶ are as previously defined, preferably R¹³, R¹⁴,and R¹⁵ are hydrogen, or C₁₋₄ alkyl, and R¹⁶ is C₆₋₂₀ aryl, mostpreferably naphthalenyl;

R^(a) independently each occurrence is C₁₋₄ alkyl, and a is 1-5, mostpreferably R^(a) in two ortho-positions to the nitrogen is isopropyl ort-butyl;

R¹⁷ and R¹⁸ independently each occurrence are hydrogen, halogen, or aC₁₋₂₀ alkyl or aryl group, most preferably one of R¹⁷ and R¹⁸ ishydrogen and the other is a C₆₋₂₀ aryl group, especially 2-isopropyl,phenyl or a fused polycyclic aryl group, most preferably an anthracenylgroup, and

bonds, optional bonds and electron pair donative interactions arerepresented by lines, dotted lines and arrows respectively.

Highly preferred metal complexes for use herein as catalyst (A)correspond to the formula:

wherein X¹ each occurrence is halide, N,N-dimethylamido, or C₁₋₄ alkyl,and preferably each occurrence X¹ is methyl;

R^(f) independently each occurrence is hydrogen, halogen, C₁₋₂₀ alkyl,or C₆₋₂₀ aryl, or two adjacent R^(f) groups are joined together therebyforming a ring, and f is 1-5; and

R^(c) independently each occurrence is hydrogen, halogen, C₁₋₂₀ alkyl,or C₆₋₂₀ aryl, or two adjacent R^(c) groups are joined together therebyforming a ring, and c is 1-5.

Additional examples of metal complexes for use as catalyst (A) accordingto the present invention are complexes of the following formulas:

wherein R^(x) is C₁₋₄ alkyl or cycloalkyl, preferably methyl, isopropyl,t-butyl or cyclohexyl; and

X¹ each occurrence is halide, N,N-dimethylamido, or C₁₋₄ alkyl,preferably methyl.

Examples of metal complexes usefully employed as catalyst (A) accordingto the present invention include:

-   [N-(2,6-di(1-methylethyl)phenyl)amido)(o-tolyl)(α-naphthalen-2-diyl(6-pyridin-2-diyl)methane)]hafnium    dimethyl;-   [N-(2,6-di(1-methylethyl)phenyl)amido)(o-tolyl)(α-naphthalen-2-diyl(6-pyridin-2-diyl)methane)]hafnium    di(N,N-dimethylamido);-   [N-(2,6-di(1-methylethyl)phenyl)amido)(o-tolyl)(α-naphthalen-2-diyl(6-pyridin-2-diyl)methane)]hafnium    dichloride;-   [N-(2,6-di(1-methylethyl)phenyl)amido)(2-isopropylphenyl)(α-naphthalen-2-diyl(6-pyridin-2-diyl)methane)]hafnium    dimethyl;-   [N-(2,6-di(1-methylethyl)phenyl)amido)(2-isopropylphenyl)(α-naphthalen-2-diyl(6-pyridin-2-diyl)methane)]hafnium    di(N,N-dimethylamido);-   [N-(2,6-di(1-methylethyl)phenyl)amido)(2-isopropylphenyl)(α-naphthalen-2-diyl(6-pyridin-2-diyl)methane)]hafnium    dichloride;-   [N-(2,6-di(-methylethyl)phenyl)amido)(phenanthren-5-yl)(α-naphthalen-2-diyl(6-pyridin-2-diyl)methane)]hafnium    dimethyl;-   [N-(2,6-di(1-methylethyl)phenyl)amido)(phenanthren-5-yl)(α-naphthalen-2-diyl(6-pyridin-2-diyl)methane)]hafnium    di(N,N-dimethylamido); and-   [N-(2,6-di(1-methylethyl)phenyl)amido)(phenanthren-5-yl)(α-naphthalen-2-diyl(6-pyridin-2-diyl)methane)]hafnium    dichloride.

Under the reaction conditions used to prepare the metal complexes usedin the present invention, the hydrogen of the 2-position of theα-naphthalene group substituted at the 6-position of the pyridin-2-ylgroup is subject to elimination, thereby uniquely forming metalcomplexes wherein the metal is covalently bonded to both the resultingamide group and to the 2-position of the α-naphthalenyl group, as wellas stabilized by coordination to the pyridinyl nitrogen atom through theelectron pair of the nitrogen atom.

Additional suitable metal complexes include compounds corresponding tothe formula:

R²⁰ is an aromatic or inertly substituted aromatic group containing from5 to 20 atoms not counting hydrogen, or a polyvalent derivative thereof;

T³ is a hydrocarbylene or silane group having from 1 to 20 atoms notcounting hydrogen, or an inertly substituted derivative thereof;

M³ is a Group 4 metal, preferably zirconium or hafnium;

G is an anionic, neutral or dianionic ligand group; preferably a halide,hydrocarbyl or dihydrocarbylamide group having up to 20 atoms notcounting hydrogen;

g is a number from 1 to 5 indicating the number of such G groups; and

bonds and electron donative interactions are represented by lines andarrows respectively.

Preferably, such complexes correspond to the formula:

T³ is a divalent bridging group of from 2 to 20 atoms not countinghydrogen, preferably a substituted or unsubstituted, C₃₋₆ alkylenegroup; and

Ar² independently each occurrence is an arylene or an alkyl- oraryl-substituted arylene group of from 6 to 20 atoms not countinghydrogen;

M³ is a Group 4 metal, preferably hafnium or zirconium;

G independently each occurrence is an anionic, neutral or dianionicligand group;

g is a number from 1 to 5 indicating the number of such X groups; and

electron donative interactions are represented by arrows.

Preferred examples of metal complexes of foregoing formula include thefollowing compounds:

where M³ is Hf or Zr;

Ar⁴ is C₆₋₂₀ aryl or inertly substituted derivatives thereof, especially3,5-di(isopropyl)phenyl, 3,5-di(isobutyl)phenyl,dibenzo-1H-pyrrole-1-yl, or anthracen-5-yl, and

T⁴ independently each occurrence comprises a C₃₋₆ alkylene group, a C₃₋₆cycloalkylene group, or an inertly substituted derivative thereof;

R²¹ independently each occurrence is hydrogen, halo, hydrocarbyl,trihydrocarbylsilyl, or trihydrocarbylsilylhydrocarbyl of up to 50 atomsnot counting hydrogen; and

G, independently each occurrence is halo or a hydrocarbyl ortrihydrocarbylsilyl group of up to 20 atoms not counting hydrogen, or 2G groups together are a divalent derivative of the foregoing hydrocarbylor trihydrocarbylsilyl groups.

Especially preferred are compounds of the formula:

wherein Ar⁴ is 3,5-di(isopropyl)phenyl, 3,5-di(isobutyl)phenyl,dibenzo-1H-pyrrole-1-yl, or anthracen-5-yl,

R²¹ is hydrogen, halo, or C₁₋₄ alkyl, especially methyl

T⁴ is propan-1,3-diyl or butan-1,4-diyl, and

G is chloro, methyl or benzyl.

Other suitable metal complexes are those of the formula:

The foregoing polyvalent Lewis base complexes are conveniently preparedby standard metallation and ligand exchange procedures involving asource of the Group 4 metal and the neutral polyfunctional ligandsource. In addition, the complexes may also be prepared by means of anamide elimination and hydrocarbylation process starting from thecorresponding Group 4 metal tetraamide and a hydrocarbylating agent,such as trimethylaluminum. Other techniques may be used as well. Thesecomplexes are known from the disclosures of, among others, U.S. Pat.Nos. 6,320,005, 6,103,657, WO 02/38628, WO 03/40195, and US 04/0220050.

Additional suitable metal complexes include Group 4-10 metal derivativescorresponding to the formula:

wherein

-   -   M² is a metal of Groups 4-10 of the Periodic Table of the        elements, preferably Group 4 metals, Ni(II) or Pd(II), most        preferably zirconium;    -   T² is a nitrogen, oxygen or phosphorus containing group;    -   X² is halo, hydrocarbyl, or hydrocarbyloxy;    -   t is one or two;    -   x″ is a number selected to provide charge balance;    -   and T² and N are linked by a bridging ligand.

Such catalysts have been previously disclosed in J. Am. Chem. Soc., 118,267-268 (1996), J. Am. Chem. Soc., 117, 6414-6415 (1995), andOrganometallics, 16, 1514-1516, (1997), among other disclosures.

Preferred examples of the foregoing metal complexes are aromatic diimineor aromatic dioxyimine complexes of Group 4 metals, especiallyzirconium, corresponding to the formula:

wherein;

M², X² and T² are as previously defined;

R^(d) independently each occurrence is hydrogen, halogen, or R^(e); and

R^(e) independently each occurrence is C₁₋₂₀ hydrocarbyl or aheteroatom-, especially a F, N, S or P-substituted derivative thereof,more preferably C₁₋₁₀ hydrocarbyl or a F or N substituted derivativethereof, most preferably alkyl, dialkylaminoalkyl, pyrrolyl,piperidenyl, perfluorophenyl, cycloalkyl, (poly)alkylaryl, or aralkyl.

Most preferred examples of the foregoing metal complexes for use ascatalyst (A) are aromatic dioxyimine complexes of zirconium,corresponding to the formula:

wherein;

X² is as previously defined, preferably C₁₋₁₀ hydrocarbyl, mostpreferably methyl or benzyl; and

R^(e)′ is methyl, isopropyl, t-butyl, cyclopentyl, cyclohexyl,2-methylcyclohexyl, 2,4-dimethylcyclohexyl, 2-pyrrolyl,N-methyl-2-pyrrolyl, 2-piperidenyl, N-methyl-2-piperidenyl, benzyl,o-tolyl, 2,6-dimethylphenyl, perfluorophenyl, 2,6-di(isopropyl)phenyl,or 2,4,6-trimethylphenyl.

The foregoing complexes also include certain phosphinimine complexes aredisclosed in EP-A-890581. These complexes correspond to the formula:[(R^(f))₃—P═N]_(f)M(K²)(R^(f))_(3-f), wherein:

R^(f) is a monovalent ligand or two R^(f) groups together are a divalentligand, preferably R^(f) is hydrogen or C₁₋₄ alkyl;

M is a Group 4 metal,

K² is a group containing delocalized n-electrons through which K² isbound to M, said K² group containing up to 50 atoms not countinghydrogen atoms, and

f is 1 or 2.

Additional suitable metal complexes include metal complexescorresponding to the formula:

where M′ is a metal of Groups 4-13, preferably Groups 8-10, mostpreferably Ni or Pd;

R^(A), R^(B) and R^(C) are univalent or neutral substituents, which alsomay be joined together to form one or more divalent substituents, and

c is a number chosen to balance the charge of the metal complex.

Preferred examples of the foregoing metal complexes for use as catalystsare compounds corresponding to the formula:

wherein M′ is Pd or Ni.

In one embodiment of the invention, branching, includinghyper-branching, may be induced in a particular segment of the presentmulti-block copolymers by the use of specific catalysts known to resultin “chain-walking” or 2,1- or 3,1-insertion in the resulting polymer.For example, certain homogeneous bridged bis indenyl- or partiallyhydrogenated bis indenyl-zirconium catalysts, disclosed by Kaminski, etal., J. Mol. Catal. A: Chemical, 102 (1995) 59-65; Zambelli, et al.,Macromolecules 1988, 21, 617-622; or Dias, et al., J. Mol. Catal. A:Chemical, 185 (2002) 57-64 may be used to prepare branched copolymersfrom single monomers. Higher transition metal catalysts, especiallynickel and palladium catalysts are also known to lead to hyper-branchedpolymers (the branches of which are also branched) as disclosed inBrookhart, et al., J. Am. Chem. Soc., 1995, 117, 64145-6415.Regio-irregular polymers possessing 2,1- and or 3,1-monomer insertionerrors are also included within the scope of the present invention.

In one embodiment of the invention, the presence of such regio-irregularmonomer addition in the polymers can be confined to only the blocks orsegments resulting from activity of catalyst A or B. Accordingly, in oneembodiment of the invention a multi-block copolymer containing blocks orsegments differing in the presence of such branching in combination withother segments or blocks substantially lacking such branching can beproduced as well as the requisite difference in tacticity betweenblocks. The presence of such branching in the multi-block copolymers ofthe invention can be detected by certain physical properties of theresulting copolymers, such as reduced surface imperfections during meltextrusion (reduced melt fracture), reduced melting point, Tg, for theamorphous segments compared to a non-branched polymer segment, and/orthe presence of regio-irregular addition errors as detected by NMRtechniques. The quantity of all the foregoing types of regio-irregularmonomer additions in the polymers of the invention (as a portion of theblocks or segments containing the same), is normally in the range from0.01 to 10 per 1,000 carbons.

Especially desired metal complexes for use as catalyst (A) are the wellknown racemic biscyclopentadienyl complexes of Group 4 metals, such asdimethylsilane or 1,2-ethylene bridged biscyclopentadienyl zirconiumcomplexes, and inertly substituted derivatives thereof. Examples includeracemic dimethylsilane or 1,2-ethylene bisindenyl complexes of Group 4metals, especially zirconium, such asethylenebis(4,5,6,7-tetrahydro-1-indenyl)dimethyl zirconium or racemicethylene bis(indenyl)dimethyl zirconium, and inertly substitutedderivatives thereof.

Suitable metal compounds for use as catalyst (B) include the foregoingmetal compounds mentioned with respect to catalyst (A) as well as othermetal compounds, with the proviso, that the tacticity of the resultingpolymer block is less than that of the block prepared by catalyst (A).

Examples of metal complexes especially suited for preparing essentiallyatactic polymers of C₃₋₂₀ α-olefins include the following metalcomplexes:

wherein R^(x) is as previously defined.

The skilled artisan will appreciate that in other embodiments of theinvention, the criterion for selecting a combination of catalyst (A) and(B) may be any other distinguishing property of the resulting polymerblocks, such as combinations based on tacticity (isotactic/syndiotactic,isotactic/atactic or syndiotactic/atactic), regio-error content, orcombinations thereof.

Cocatalysts

Each of the metal complex catalysts (A) and (B) (also interchangeablyreferred to herein as procatalysts) may be activated to form the activecatalyst composition by combination with a cocatalyst, preferably acation forming cocatalyst, a strong Lewis acid, or a combinationthereof. In a preferred embodiment, the shuttling agent is employed bothfor purposes of chain shuttling and as the cocatalyst component of thecatalyst composition.

The metal complexes desirably are rendered catalytically active bycombination with a cation forming cocatalyst, such as those previouslyknown in the art for use with Group 4 metal olefin polymerizationcomplexes. Suitable cation forming cocatalysts for use herein includeneutral Lewis acids, such as C₁₋₃₀ hydrocarbyl substituted Group 13compounds, especially tri(hydrocarbyl)aluminum- or tri(hydrocarbyl)boroncompounds and halogenated (including perhalogenated) derivativesthereof, having from 1 to 10 carbons in each hydrocarbyl or halogenatedhydrocarbyl group, more especially perfluorinated tri(aryl)boroncompounds, and most especially tris(pentafluoro-phenyl)borane;nonpolymeric, compatible, noncoordinating, ion forming compounds(including the use of such compounds under oxidizing conditions),especially the use of ammonium-, phosphonium-, oxonium-, carbonium-,silylium- or sulfonium-salts of compatible, noncoordinating anions, orferrocenium-, lead- or silver salts of compatible, noncoordinatinganions; and combinations of the foregoing cation forming cocatalysts andtechniques. The foregoing activating cocatalysts and activatingtechniques have been previously taught with respect to different metalcomplexes for olefin polymerizations in the following references:EP-A-277,003, U.S. Pat. No. 5,153,157, U.S. Pat. No. 5,064,802, U.S.Pat. No. 5,321,106, U.S. Pat. No. 5,721,185, U.S. Pat. No. 5,350,723,U.S. Pat. No. 5,425,872, U.S. Pat. No. 5,625,087, U.S. Pat. No.5,883,204, U.S. Pat. No. 5,919,983, U.S. Pat. No. 5,783,512, WO99/15534, and WO99/42467.

Combinations of neutral Lewis acids, especially the combination of atrialkyl aluminum compound having from 1 to 4 carbons in each alkylgroup and a halogenated tri(hydrocarbyl)boron compound having from 1 to20 carbons in each hydrocarbyl group, especiallytris(pentafluorophenyl)borane, further combinations of such neutralLewis acid mixtures with a polymeric or oligomeric alumoxane, andcombinations of a single neutral Lewis acid, especiallytris(pentafluorophenyl)borane with a polymeric or oligomeric alumoxanemay be used as activating cocatalysts. Preferred molar ratios of metalcomplex:tris(pentafluorophenyl-borane:alumoxane are from 1:1:1 to1:5:20, more preferably from 1:1:1.5 to 1:5:10.

Suitable ion forming compounds useful as cocatalysts in one embodimentof the present invention comprise a cation which is a Bronsted acidcapable of donating a proton, and a compatible, noncoordinating anion,A⁻. As used herein, the term “noncoordinating” means an anion orsubstance which either does not coordinate to the Group 4 metalcontaining precursor complex and the catalytic derivative derived therefrom, or which is only weakly coordinated to such complexes therebyremaining sufficiently labile to be displaced by a neutral Lewis base. Anoncoordinating anion specifically refers to an anion which whenfunctioning as a charge balancing anion in a cationic metal complex doesnot transfer an anionic substituent or fragment thereof to said cationthereby forming neutral complexes. “Compatible anions” are anions whichare not degraded to neutrality when the initially formed complexdecomposes and are noninterfering with desired subsequent polymerizationor other uses of the complex.

Preferred anions are those containing a single coordination complexcomprising a charge-bearing metal or metalloid core which anion iscapable of balancing the charge of the active catalyst species (themetal cation) which may be formed when the two components are combined.Also, said anion should be sufficiently labile to be displaced byolefinic, diolefinic and acetylenically unsaturated compounds or otherneutral Lewis bases such as ethers or nitrites. Suitable metals include,but are not limited to, aluminum, gold and platinum. Suitable metalloidsinclude, but are not limited to, boron, phosphorus, and silicon.Compounds containing anions which comprise coordination complexescontaining a single metal or metalloid atom are, of course, well knownand many, particularly such compounds containing a single boron atom inthe anion portion, are available commercially.

Preferably such cocatalysts may be represented by the following generalformula:

(L*−H)_(g) ⁺(A)^(g−)

wherein:

L* is a neutral Lewis base;

(L*-H)⁺ is a conjugate Bronsted acid of L*;

A^(g−) is a noncoordinating, compatible anion having a charge of g−, and

g is an integer from 1 to 3.

More preferably A^(g−) corresponds to the formula: [M′Q₄]⁻;

wherein:

M′ is boron or aluminum in the +3 formal oxidation state; and

Q independently each occurrence is selected from hydride, dialkylamido,halide, hydrocarbyl, hydrocarbyloxide, halosubstituted-hydrocarbyl,halosubstituted hydrocarbyloxy, and halo-substituted silylhydrocarbylradicals (including perhalogenated hydrocarbyl-perhalogenatedhydrocarbyloxy- and perhalogenated silylhydrocarbyl radicals), said Qhaving up to 20 carbons with the proviso that in not more than oneoccurrence is Q halide. Examples of suitable hydrocarbyloxide Q groupsare disclosed in U.S. Pat. No. 5,296,433.

In a more preferred embodiment, d is one, that is, the counter ion has asingle negative charge and is A⁻. Activating cocatalysts comprisingboron which are particularly useful in the preparation of catalysts ofthis invention may be represented by the following general formula:

(L*-H)⁺(BQ₄)⁻;

wherein:

L* is as previously defined;

B is boron in a formal oxidation state of 3; and

Q is a hydrocarbyl-, hydrocarbyloxy-, fluorinated hydrocarbyl-,fluorinated hydrocarbyloxy-, or fluorinated silylhydrocarbyl-group of upto 20 nonhydrogen atoms, with the proviso that in not more than oneoccasion is Q hydrocarbyl.

Preferred Lewis base salts are ammonium salts, more preferablytrialkylammonium salts containing one or more C₁₂₄₀ alkyl groups. Mostpreferably, Q is each occurrence a fluorinated aryl group, especially, apentafluorophenyl group.

Illustrative, but not limiting, examples of boron compounds which may beused as an activating cocatalyst in the preparation of the improvedcatalysts of this invention are tri-substituted ammonium salts such as:

-   trimethylammonium tetrakis(pentafluorophenyl)borate,-   triethylammonium tetrakis(pentafluorophenyl)borate,-   tripropylammonium tetrakis(pentafluorophenyl)borate,-   tri(n-butyl)ammonium tetrakis(pentafluorophenyl)borate,-   tri(sec-butyl)ammonium tetrakis(pentafluorophenyl)borate,-   N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate,-   N,N-dimethylanilinium n-butyltris(pentafluorophenyl)borate,-   N,N-dimethylanilinium benzyltris(pentafluorophenyl)borate,-   N,N-dimethylanilinium    tetrakis(4-(t-butyldimethylsilyl)-2,3,5,6-tetrafluorophenyl)borate,-   N,N-dimethylanilinium    tetrakis(4-(triisopropylsilyl)-2,3,5,6-tetrafluorophenyl)borate,-   N,N-dimethylanilinium    pentafluorophenoxytris(pentafluorophenyl)borate,-   N,N-diethylanilinium tetrakis(pentafluorophenyl)borate,-   N,N-dimethyl-2,4,6-trimethylanilinium    tetrakis(pentafluorophenyl)borate,-   dimethyloctadecylammonium tetrakis(pentafluorophenyl)borate,-   methyldioctadecylammonium tetrakis(pentafluorophenyl)borate,    dialkyl ammonium salts such as:-   di-(i-propyl)ammonium tetrakis(pentafluorophenyl)borate,-   methyloctadecylammonium tetrakis(pentafluorophenyl)borate,-   methyloctadodecylammonium tetrakis(pentafluorophenyl)borate, and-   dioctadecylammonium tetrakis(pentafluorophenyl)borate;    tri-substituted phosphonium salts such as:-   triphenylphosphonium tetrakis(pentafluorophenyl)borate,-   methyldioctadecylphosphonium tetrakis(pentafluorophenyl)borate, and-   tri(2,6-dimethylphenyl)phosphonium    tetrakis(pentafluorophenyl)borate;    di-substituted oxonium salts such as:-   diphenyloxonium tetrakis(pentafluorophenyl)borate,-   di(o-tolyl)oxonium tetrakis(pentafluorophenyl)borate, and-   di(octadecyl)oxonium tetrakis(pentafluorophenyl)borate;    di-substituted sulfonium salts such as:

di(o-tolyl)sulfonium tetrakis(pentafluorophenyl)borate, and

-   methylcotadecylsulfonium tetrakis(pentafluorophenyl)borate.

Preferred (L*-H)⁺ cations are methyldioctadecylammonium cations,dimethyloctadecylammonium cations, and ammonium cations derived frommixtures of trialkyl amines containing one or 2 C₁₄₋₁₈ alkyl groups.

Another suitable ion forming, activating cocatalyst comprises a salt ofa cationic oxidizing agent and a noncoordinating, compatible anionrepresented by the formula:

(Ox^(h+))_(g)(A^(g−))_(la),

wherein:

Ox^(h+) is a cationic oxidizing agent having a charge of h+;

h is an integer from 1 to 3; and

A^(g−) and g are as previously defined.

Examples of cationic oxidizing agents include: ferrocenium,hydrocarbyl-substituted ferrocenium, Ag⁺′ or Pb⁺². Preferred embodimentsof A^(g−) are those anions previously defined with respect to theBronsted acid containing activating cocatalysts, especiallytetrakis(pentafluorophenyl)borate.

Another suitable ion forming, activating cocatalyst comprises a compoundwhich is a salt of a carbenium ion and a noncoordinating, compatibleanion represented by the formula:

[C]⁺A⁻

wherein:

[C]⁺ is a C₁₋₂₀ carbenium ion; and

A⁻ is a noncoordinating, compatible anion having a charge of −1. Apreferred carbenium ion is the trityl cation, that istriphenylmethylium.

A further suitable ion forming, activating cocatalyst comprises acompound which is a salt of a silylium ion and a noncoordinating,compatible anion represented by the formula:

(Q¹ ₃Si)⁺A⁻

wherein:

Q¹ is C₁₋₁₀ hydrocarbyl, and A⁻ is as previously defined.

Preferred silylium salt activating cocatalysts are trimethylsilyliumtetrakispentafluorophenylborate, triethylsilyliumtetrakispentafluorophenylborate and ether substituted adducts thereof.Silylium salts have been previously generically disclosed in J. Chem.Soc. Chem. Comm., 1993, 383-384, as well as Lambert, J. B., et al.,Organometallics, 1994, 13, 2430-2443. The use of the above silyliumsalts as activating cocatalysts for addition polymerization catalysts isdisclosed in U.S. Pat. No. 5,625,087.

Certain complexes of alcohols, mercaptans, silanols, and oximes withtris(pentafluorophenyl)borane are also effective catalyst activators andmay be used according to the present invention. Such cocatalysts aredisclosed in U.S. Pat. No. 5,296,433.

Suitable activating cocatalysts for use herein also include polymeric oroligomeric alumoxanes, especially methylalumoxane (MAO), triisobutylaluminum modified methylalumoxane (MMAO), or isobutylalumoxane; Lewisacid modified alumoxanes, especially perhalogenatedtri(hydrocarbyl)aluminium- or perhalogenated tri(hydrocarbyl)boronmodified alumoxanes, having from 1 to 10 carbons in each hydrocarbyl orhalogenated hydrocarbyl group, and most especiallytris(pentafluorophenyl)borane modified alumoxanes. Such cocatalysts arepreviously disclosed in U.S. Pat. Nos. 6,214,760, 6,160,146, 6,140,521,and 6,696,379.

A class of cocatalysts comprising non-coordinating anions genericallyreferred to as expanded anions, further disclosed in U.S. Pat. No.6,395,671, may be suitably employed to activate the metal complexes ofthe present invention for olefin polymerization. Generally, thesecocatalysts (illustrated by those having imidazolide, substitutedimidazolide, imidazolinide, substituted imidazolinide, benzimidazolide,or substituted benzimidazolide anions) may be depicted as follows:

wherein:

A*⁺ is a cation, especially a proton containing cation, and preferablyis a trihydrocarbyl ammonium cation containing one or two C₁₀₋₄₀ alkylgroups, especially a methyldi (C₁₄₋₂₀ alkyl)ammonium cation,

Q³, independently each occurrence, is hydrogen or a halo, hydrocarbyl,halocarbyl, halohydrocarbyl, silylhydrocarbyl, or silyl, (includingmono-, di- and tri(hydrocarbyl)silyl) group of up to 30 atoms notcounting hydrogen, preferably C₁₋₂₀ alkyl, and

Q² is tris(pentafluorophenyl)borane or tris(pentafluorophenyl)alumane).

Examples of these catalyst activators includetrihydrocarbylammonium-salts, especially, methyldi(C₁₄₋₂₀alkyl)ammonium-salts of:

-   bis(tris(pentafluorophenyl)borane)imidazolide,-   bis(tris(pentafluorophenyl)borane)-2-undecylimidazolide,-   bis(tris(pentafluorophenyl)borane)-2-heptadecylimidazolide,-   bis(tris(pentafluorophenyl)borane)-4,5-bis(undecyl)imidazolide,-   bis(tris(pentafluorophenyl)borane)-4,5-bis(heptadecyl)imidazolide,-   bis(tris(pentafluorophenyl)borane)imidazolinide,-   bis(tris(pentafluorophenyl)borane)-2-undecylimidazolinide,-   bis(tris(pentafluorophenyl)borane)-2-heptadecylimidazolinide,-   bis(tris(pentafluorophenyl)borane)-4,5-bis(undecyl)imidazolinide,-   bis(tris(pentafluorophenyl)borane)-4,5-bis(heptadecyl)imidazolinide,    bis(tris(pentafluorophenyl)borane)-5,6-dimethylbenzimidazolide,-   bis(tris(pentafluorophenyl)borane)-5,6-bis(undecyl)benzimidazolide,-   bis(tris(pentafluorophenyl)alumane)imidazolide,-   bis(tris(pentafluorophenyl)alumane)-2-undecylimidazolide,-   bis(tris(pentafluorophenyl)alumane)-2-heptadecylimidazolide,-   bis(tris(pentafluorophenyl)alumane)-4,5-bis(undecyl)imidazolide,-   bis(tris(pentafluorophenyl)alumane)-4,5-bis(heptadecyl)imidazolide,-   bis(tris(pentafluorophenyl)alumane)imidazolinide,-   bis(tris(pentafluorophenyl)alumane)-2-undecylimidazolinide,-   bis(tris(pentafluorophenyl)alumane)-2-heptadecylimidazolinide,-   bis(tris(pentafluorophenyl)alumane)-4,5-bis(undecyl)imidazolinide,-   bis(tris(pentafluorophenyl)alumane)-4,5-bis(heptadecyl)imidazolinide,-   bis(tris(pentafluorophenyl)alumane)-5,6-dimethylbenzimidazolide, and-   bis(tris(pentafluorophenyl)alumane)-5,6-bis(undecyl)benzimidazolide.

Other activators include those described in PCT publication WO 98/07515such as tris(2, 2′,2″-nonafluorobiphenyl)fluoroaluminate. Combinationsof activators are also contemplated by the invention, for example,alumoxanes and ionizing activators in combinations, see for example,EP-A-0 573120, PCT publications WO 94/07928 and WO 95/14044 and U.S.Pat. Nos. 5,153,157 and 5,453,410. WO 98/09996 describes activatingcatalyst compounds with perchlorates, periodates and iodates, includingtheir hydrates. WO 99/18135 describes the use of organoboroaluminuinactivators. WO 03/10171 discloses catalyst activators that are adductsof Bronsted acids with Lewis acids. Other activators or methods foractivating a catalyst compound are described in for example, U.S. Pat.Nos. 5,849,852, 5,859,653, 5,869,723, EP-A-615981, and PCT publicationWO 98/32775. All of the foregoing catalyst activators as well as anyother know activator for transition metal complex catalysts may beemployed alone or in combination according to the present invention,however, for best results alumoxane containing cocatalysts are avoided.

The molar ratio of catalyst/cocatalyst employed preferably ranges from1:10,000 to 100:1, more preferably from 1:5000 to 10:1, most preferablyfrom 1:1000 to 1:1. Alumoxane, when used by itself as an activatingcocatalyst, is employed in large quantity, generally at least 100 timesthe quantity of metal complex on a molar basis.Tris(pentafluorophenyl)borane, where used as an activating cocatalyst isemployed in a molar ratio to the metal complex of from 0.5:1 to 10:1,more preferably from 1:1 to 6:1 most preferably from 1:1 to 5:1. Theremaining activating cocatalysts are generally employed in approximatelyequimolar quantity with the metal complex.

The process of the invention employing catalyst A, catalyst B, one ormore cocatalysts, and chain shuttling agent C may be further elucidatedby reference to FIG. 1, where there are illustrated activated catalystsite A, 10, which under polymerization conditions forms a polymer chain,13, attached to the active catalyst site, 12. Similarly, active catalystsite B, 20, produces a differentiated polymer chain, 23, attached to theactive catalyst site, 22. A chain shuttling agent C1, attached to apolymer chain produced by active catalyst B, 14, exchanges its polymerchain, 23, for the polymer chain, 13, attached to catalyst site A.Additional chain growth under polymerization conditions causes formationof a multi-block copolymer, 18, attached to active catalyst site A.Similarly, chain shuttling agent C2, attached to a polymer chainproduced by active catalyst site A, 24, exchanges its polymer chain, 13,for the polymer chain, 23, attached to catalyst site B. Additional chaingrowth under polymerization conditions causes formation of a multi-blockcopolymer, 28, attached to active catalyst site B. The growingmulti-block copolymers are repeatedly exchanged between active catalystA and active catalyst B by means of shuttling agent C resulting information of a block or segment of differing properties wheneverexchange to the opposite active catalyst site occurs. The growingpolymer chains may be recovered while attached to a chain shuttlingagent and functionalized if desired. Alternatively, the resultingpolymer may be recovered by scission from the active catalyst site orthe shuttling agent, through use of a proton source or other killingagent.

It is believed (without wishing to be bound by such belief), that thecomposition of the respective segments or blocks, and especially of theend segments of the polymer chains, may be influenced through selectionof process conditions or other process variables. In the polymers of theinvention, the nature of the end segments is determined by the relativerates of chain transfer or termination for the respective catalysts aswell as by the relative rates of chain shuttling. Possible chaintermination mechanisms include, but are not limited to, β-hydrogenelimination, β-hydrogen transfer to monomer, β-methyl elimination, andchain transfer to hydrogen or other chain-terminating reagent such as anorganosilane or chain functionalizing agent. Accordingly, when a lowconcentration of chain shuttling agent is used, the majority of polymerchain ends will be generated in the polymerization reactor by one of theforegoing chain termination mechanisms and the relative rates of chaintermination for catalyst (A) and (B) will determine the predominantchain terminating moiety. That is, the catalyst having the fastest rateof chain termination will produce relatively more chain end segments inthe finished polymer.

In contrast, when a high concentration of chain shuttling agent isemployed, the majority of the polymer chains within the reactor and uponexiting the polymerization zone are attached or bound to the chainshuttling agent. Under these reaction conditions, the relative rates ofchain transfer of the polymerization catalysts and the relative rate ofchain shuttling of the two catalysts primarily determines the identityof the chain terminating moiety. If catalyst (A) has a faster chaintransfer and/or chain shuttling rate than catalyst (B), then themajority of the chain end segments will be those produced by catalyst(A).

At intermediate concentrations of chain shuttling agent, all three ofthe aforementioned factors are instrumental in determining the identityof the final polymer block. The foregoing methodology may be expanded tothe analysis of multi-block polymers having more than two block typesand for controlling the average block lengths and block sequences forthese polymers. For example, using a mixture of catalysts 1, 2, and 3with a chain shuttling agent, for which each catalyst type makes adifferent type of polymer block, produces a linear block copolymer withthree different block types. Furthermore, if the ratio of the shuttlingrate to the propagation rate for the three catalysts follows the order1>2>3, then the average block length for the three block types willfollow the order 3>2>1, and there will be fewer instances of 2-typeblocks adjacent to 3-type blocks than 1-type blocks adjacent to 2-typeblocks.

It follows that a method exists for controlling the block lengthdistribution of the various block types. For example, by selectingcatalysts 1, 2, and 3 (wherein 2 and 3 produce substantially the samepolymer block type), and a chain shuttling agent, and the shuttling ratefollows the order 1 >2>3, the resulting polymer will have a bimodaldistribution of block lengths made from the 2 and 3 catalysts.

During the polymerization, the reaction mixture comprising the monomerof interest is contacted with the activated catalyst compositionaccording to any suitable polymerization conditions. The process ischaracterized by use of elevated temperatures and pressures. Hydrogenmay be employed as a chain transfer agent for molecular weight controlaccording to known techniques if desired. As in other similarpolymerizations, it is highly desirable that the monomer(s) and solventsemployed be of sufficiently high purity that catalyst deactivation doesnot occur. Any suitable technique for monomer purification such asdevolatilization at reduced pressure, contacting with molecular sievesor high surface area alumina, or a combination of the foregoingprocesses may be employed. The skilled artisan will appreciate that theratio of chain shuttling agent to one or more catalysts and or monomersin the process of the present invention may be varied in order toproduce polymers differing in one or more chemical or physicalproperties.

Supports may be employed in the present invention, especially in slurryor gas-phase polymerizations. Suitable supports include solid,particulated, high surface area, metal oxides, metalloid oxides, ormixtures thereof (interchangeably referred to herein as an inorganicoxide). Examples include: talc, silica, alumina, magnesia, titania,zirconia, Sn₂O₃, aluminosilicates, borosilicates, clays, and mixturesthereof. Suitable supports preferably have a surface area as determinedby nitrogen porosimetry using the B.E.T. method from 10 to 1000 m²/g,and preferably from 100 to 600 m²/g. The average particle size typicallyis from 0.1 to 500 μm, preferably from 1 to 200 μm, more preferably 10to 100 μm.

In one embodiment of the invention the present catalyst composition andoptional support may be spray dried or otherwise recovered in solid,particulated form to provide a composition that is readily transportedand handled. Suitable methods for spray drying a liquid containingslurry are well known in the art and usefully employed herein. Preferredtechniques for spray drying catalyst compositions for use herein aredescribed in U.S. Pat. Nos. 5,648,310 and 5,672,669.

The polymerization is desirably carried out as a continuouspolymerization, preferably a continuous, solution polymerization, inwhich catalyst components, shuttling agent(s), monomer(s), andoptionally solvent, adjuvants, scavengers, and polymerization aids arecontinuously supplied to the reaction zone and polymer productcontinuously removed there from. Within the scope of the terms“continuous” and “continuously” as used in this context are thoseprocesses in which there are intermittent additions of reactants andremoval of products at small regular or irregular intervals, so that,over time, the overall process is substantially continuous.

The catalyst compositions can be advantageously employed in a highpressure, solution, slurry, or gas phase polymerization process. For asolution polymerization process it is desirable to employ homogeneousdispersions of the catalyst components in a liquid diluent in which thepolymer is soluble under the polymerization conditions employed. Onesuch process utilizing an extremely fine silica or similar dispersingagent to produce such a homogeneous catalyst dispersion where either themetal complex or the cocatalyst is only poorly soluble is disclosed inU.S. Pat. No. 5,783,512. A solution process to prepare the novelpolymers of the present invention, especially a continuous solutionprocess is preferably carried out at a temperature between 80° C. and250° C., more preferably between 100° C. and 210° C., and mostpreferably between 110° C. and 210° C. A high pressure process isusually carried out at temperatures from 100° C. to 400° C. and atpressures above 500 bar (50 MPa). A slurry process typically uses aninert hydrocarbon diluent and temperatures of from 0° C. up to atemperature just below the temperature at which the resulting polymerbecomes substantially soluble in the inert polymerization medium.Preferred temperatures in a slurry polymerization are from 30° C.,preferably from 60° C. up to 115° C., preferably up to 100° C. Pressurestypically range from atmospheric (100 kPa) to 500 psi (3.4 MPa).

In all of the foregoing processes, continuous or substantiallycontinuous polymerization conditions are preferably employed. The use ofsuch polymerization conditions, especially continuous, solutionpolymerization processes employing two or more active polymerizationcatalyst species, allows the use of elevated reactor temperatures whichresults in the economical production of multi-block or segmentedcopolymers in high yields and efficiencies. Both homogeneous andplug-flow type reaction conditions may be employed. The latterconditions are preferred where tapering of the block composition isdesired.

Both catalyst compositions (A) and (B) may be prepared as a homogeneouscomposition by addition of the requisite metal complexes to a solvent inwhich the polymerization will be conducted or in a diluent compatiblewith the ultimate reaction mixture. The desired cocatalyst or activatorand the shuttling agent may be combined with the catalyst compositioneither prior to, simultaneously with, or after combination with themonomers to be polymerized and any additional reaction diluent.

At all times, the individual ingredients as well as any active catalystcomposition must be protected from oxygen and moisture. Therefore, thecatalyst components, shuttling agent and activated catalysts must beprepared and stored in an oxygen and moisture free atmosphere,preferably a dry, inert gas such as nitrogen.

Without limiting in any way the scope of the invention, one means forcarrying out such a polymerization process is as follows. In astirred-tank reactor, the monomers to be polymerized are introducedcontinuously together with any solvent or diluent. The reactor containsa liquid phase composed substantially of monomers together with anysolvent or diluent and dissolved polymer. Preferred solvents includeC₄₋₁₀ hydrocarbons or mixtures thereof, especially alkanes such ashexane or mixtures of alkanes, as well as one or more of the monomersemployed in the polymerization.

The mixture of two or more catalysts along with cocatalyst and chainshuttling agent are continuously or intermittently introduced in thereactor liquid phase or any recycled portion thereof. The reactortemperature and pressure may be controlled by adjusting thesolvent/monomer ratio, the catalyst addition rate, as well as by coolingor heating coils, jackets or both. The polymerization rate is controlledby the rate of catalyst addition. The comonomer content (if any) of thepolymer product is determined by the ratio of major monomer to comonomerin the reactor, which is controlled by manipulating the respective feedrates of these components to the reactor. The polymer product molecularweight is controlled, optionally, by controlling other polymerizationvariables such as the temperature, monomer concentration, or by thepreviously mentioned chain transfer agent, as is well known in the art.Upon exiting the reactor, the effluent is contacted with a catalyst killagent such as water, steam or an alcohol. The polymer solution isoptionally heated, and the polymer product is recovered by flashing offgaseous monomers as well as residual solvent or diluent at reducedpressure, and, if necessary, conducting further devolatilization inequipment such as a devolatilizing extruder. In a continuous process themean residence time of the catalyst and polymer in the reactor generallyis from 5 minutes to 8 hours, and preferably from 10 minutes to 6 hours.

Alternatively, the foregoing polymerization may be carried out in acontinuous loop reactor with or without a monomer, catalyst or shuttlingagent gradient established between differing regions thereof, optionallyaccompanied by separated addition of catalysts and/or chain transferagent, and operating under adiabatic or non-adiabatic solutionpolymerization conditions or combinations of the foregoing reactorconditions. Examples of suitable loop reactors and a variety of suitableoperating conditions for use therewith are found in U.S. Pat. Nos.5,977,251, 6,319,989 and 6,683,149.

Although not as desired, the catalyst composition may also be preparedand employed as a heterogeneous catalyst by adsorbing the requisitecomponents on an inert inorganic or organic particulated solid, aspreviously disclosed. In an preferred embodiment, a heterogeneouscatalyst is prepared by co-precipitating the metal complex and thereaction product of an inert inorganic compound and an active hydrogencontaining activator, especially the reaction product of a tri (C₁₋₄alkyl) aluminum compound and an ammonium salt of ahydroxyaryltris(pentafluorophenyl)borate, such as an ammonium salt of(4-hydroxy-3,5-ditertiarybutylphenyl)tris(pentafluorophenyl)borate. Whenprepared in heterogeneous or supported form, the catalyst compositionmay be employed in a slurry or a gas phase polymerization. As apractical limitation, slurry polymerization takes place in liquiddiluents in which the polymer product is substantially insoluble.Preferably, the diluent for slurry polymerization is one or morehydrocarbons with less than 5 carbon atoms. If desired, saturatedhydrocarbons such as ethane, propane or butane may be used in whole orpart as the diluent. As with a solution polymerization, the monomer or amixture of different monomers may be used in whole or part as thediluent. Most preferably at least a major part of the diluent comprisesthe monomers to be polymerized.

Preferably for use in gas phase polymerization processes, the supportmaterial and resulting catalyst has a median particle diameter from 20to 200 μm, more preferably from 30 μm to 150 μm, and most preferablyfrom 50 μm to 100 μm. Preferably for use in slurry polymerizationprocesses, the support has a median particle diameter from 1 μm to 200μm, more preferably from 5 μm to 100 μm, and most preferably from 10 μmto 80 μm.

Suitable gas phase polymerization process for use herein aresubstantially similar to known processes used commercially on a largescale for the manufacture of polypropylene, poly-4-methyl-1-pentene, andother olefin polymers. The gas phase process employed can be, forexample, of the type which employs a mechanically stirred bed or a gasfluidized bed as the polymerization reaction zone. Preferred is theprocess wherein the polymerization reaction is carried out in a verticalcylindrical polymerization reactor containing a fluidized bed of polymerparticles supported or suspended above a perforated plate orfluidization grid, by a flow of fluidization gas.

The gas employed to fluidize the bed comprises the monomer or monomersto be polymerized, and also serves as a heat exchange medium to removethe heat of reaction from the bed. The hot gases emerge from the top ofthe reactor, normally via a tranquilization zone, also known as avelocity reduction zone, having a wider diameter than the fluidized bedand wherein fine particles entrained in the gas stream have anopportunity to gravitate back into the bed. It can also be advantageousto use a cyclone to remove ultra-fine particles from the hot gas stream.The gas is then normally recycled to the bed by means of a blower orcompressor and one or more heat exchangers to strip the gas of the heatof polymerization.

A preferred method of cooling of the bed, in addition to the coolingprovided by the cooled recycle gas, is to feed a volatile liquid to thebed to provide an evaporative cooling effect, often referred to asoperation in the condensing mode. The volatile liquid employed in thiscase can be, for example, a volatile inert liquid, for example, asaturated hydrocarbon having 3 to 8, preferably 4 to 6, carbon atoms. Inthe case that the monomer or comonomer itself is a volatile liquid, orcan be condensed to provide such a liquid, this can suitably be fed tothe bed to provide an evaporative cooling effect. The volatile liquidevaporates in the hot fluidized bed to form gas which mixes with thefluidizing gas. If the volatile liquid is a monomer or comonomer, itwill undergo some polymerization in the bed. The evaporated liquid thenemerges from the reactor as part of the hot recycle gas, and enters thecompression/heat exchange part of the recycle loop. The recycle gas iscooled in the heat exchanger and, if the temperature to which the gas iscooled is below the dew point, liquid will precipitate from the gas.This liquid is desirably recycled continuously to the fluidized bed. Itis possible to recycle the precipitated liquid to the bed as liquiddroplets carried in the recycle gas stream. This type of process isdescribed, for example in EP-89691; U.S. Pat. No. 4,543,399; WO-94/25495and U.S. Pat. No. 5,352,749. A particularly preferred method ofrecycling the liquid to the bed is to separate the liquid from therecycle gas stream and to reinject this liquid directly into the bed,preferably using a method which generates fine droplets of the liquidwithin the bed. This type of process is described in WO-94/28032.

The polymerization reaction occurring in the gas fluidized bed iscatalyzed by the continuous or semi-continuous addition of catalystcomposition according to the invention. The catalyst composition may besubjected to a prepolymerization step, for example, by polymerizing asmall quantity of olefin monomer in a liquid inert diluent, to provide acatalyst composite comprising supported catalyst particles embedded inolefin polymer particles as well.

The polymer is produced directly in the fluidized bed by polymerizationof the monomer or mixture of monomers on the fluidized particles ofcatalyst composition, supported catalyst composition or prepolymerizedcatalyst composition within the bed. Start-up of the polymerizationreaction is achieved using a bed of preformed polymer particles, whichare preferably similar to the desired polymer, and conditioning the bedby drying with inert gas or nitrogen prior to introducing the catalystcomposition, the monomers and any other gases which it is desired tohave in the recycle gas stream, such as a diluent gas, hydrogen chaintransfer agent, or an inert condensable gas when operating in gas phasecondensing mode. The produced polymer is discharged continuously orsemi-continuously from the fluidized bed as desired.

The gas phase processes most suitable for the practice of this inventionare continuous processes which provide for the continuous supply ofreactants to the reaction zone of the reactor and the removal ofproducts from the reaction zone of the reactor, thereby providing asteady-state environment on the macro scale in the reaction zone of thereactor. Products are readily recovered by exposure to reduced pressureand optionally elevated temperatures (devolatilization) according toknown techniques. Typically, the fluidized bed of the gas phase processis operated at temperatures greater than 50° C., preferably from 60° C.to 110° C., more preferably from 70° C. to 110° C.

Examples of gas phase processes which are adaptable for use in theprocess of this invention are disclosed in U.S. Pat. Nos. 4,588,790;4,543,399; 5,352,749; 5,436,304; 5,405,922; 5,462,999; 5,461,123;5,453,471; 5,032,562; 5,028,670; 5,473,028; 5,106,804; 5,556,238;5,541,270; 5,608,019; and 5,616,661.

As previously mentioned, functionalized derivatives of multi-blockcopolymers are also included within the present invention. Examplesinclude metallated polymers wherein the metal is the remnant of thecatalyst or chain shuttling agent employed, as well as furtherderivatives thereof, for example, the reaction product of a metallatedpolymer with an oxygen source and then with water to form a hydroxylterminated polymer. In another embodiment, sufficient air or otherquench agent is added to cleave some or all of the shuttlingagent-polymer bonds thereby converting at least a portion of the polymerto a hydroxyl terminated polymer. Additional examples include olefinterminated polymers formed by β-hydride elimination and ethylenicunsaturation in the resulting polymer.

In one embodiment of the invention the multi-block copolymer may befunctionalized by maleation (reaction with maleic anhydride or itsequivalent), metallation (such as with an alkyl lithium reagent,optionally in the presence of a Lewis base, especially an amine, such astetramethylethylenediamine), or by incorporation of a diene or maskedolefin in a copolymerization process. After polymerization involving amasked olefin, the masking group, for example a trihydrocarbylsilane,may be removed thereby exposing a more readily functionalized remnant.Techniques for functionalization of polymers are well known, anddisclosed for example in U.S. Pat. No. 5,543,458, and elsewhere.

Because a substantial fraction of the polymeric product exiting thereactor is terminated with the chain shuttling agent, furtherfunctionalization is relatively easy. The metallated polymer species canbe utilized in well known chemical reactions such as those suitable forother alkyl-aluminum, alkyl-gallium, alkyl-zinc, or alkyl-Group 1compounds to form amine-, hydroxy-, epoxy-, ketone-, ester-, nitrile-and other functionalized terminated polymer products. Examples ofsuitable reaction techniques that are adaptable for use here in aredescribed in Negishi, “Organometallics in Organic Synthesis”, Vol. 1 and2, (1980), and other standard texts in organometallic and organicsynthesis.

Polymer Products

Utilizing the present process, novel polymers, especially multi-blockcopolymers of propylene, 4-methyl-1-pentene, or another C₄₋₂₀ α-olefincomonomer, having multiple blocks or segments of differing tacticity arereadily prepared. Highly desirably, the polymers are interpolymerscomprising in polymerized form propylene or 4-methyl-1-pentene.

Tacticity in the resulting interpolymers may be measured using anysuitable technique, with techniques based on nuclear magnetic resonance(NMR) spectroscopy preferred. It is highly desirable that some or all ofthe polymer blocks comprise an isotactic polymer, preferably a highlyisotactic polypropylene or poly-4-methyl-1-pentene, and any remainingpolymer blocks predominantly comprise atactic polymer, especiallyatactic polypropylene or poly-4-methyl-1-pentene. Preferably the tacticsegments or blocks are highly isotactic polypropylene orpoly-4-methyl-1-pentene, especially homopolymers containing at least 99mole percent propylene or 4-methyl-1-pentene therein.

Further preferably, the interpolymers of the invention comprise from 10to 90 mole percent tactic segments and 90 to 10 mole percent atacticcopolymer segments. Regio-irregular branching in the polymers of theinvention may also arise as a result of chain walking or other branchforming process. In the instance where chain walking in thepolymerization of a C₄₋₂₀ α-olefin occurs, the catalyst chain may “walk”to the terminal methyl unit of the monomer before inserting anothermonomer. Such insertions may include 1,ω- or 2,ω-insertions, and lead toeither chain straightening or to differences in chain branching and/orlowered Tg in the segments containing the same. Specifically,1,ω-insertions generally lead to a reduction in branching compared to anormal polymer. In addition, 2-ω insertions result in the formation ofmethyl branches. These insertions are included within the term“regio-irregular monomer insertion” or “regio-irregular branching” asused herein. Among the tactic copolymer segments, those containingregio-irregular monomer additions may range from 15 to 100 percent,preferably from 50 to 100 percent of such blocks. Regio-irregularinsertions in such polymers generally are less than or equal to 5percent, preferably less than or equal to 2 percent, and most preferablyless than or equal to 1 percent of monomer insertions as determined by¹³C NMR.

Certain of the foregoing regio-irregular monomer additions in the tacticpolymer segment characterize one embodiment of the invention.Specifically, such errors are identifiable by ¹³C NMR peaks at 14.6 and15.7 ppm, the peaks being of approximately equal intensity andrepresenting up to 5 mole percent, preferably from 0.1 to 5.0 molepercent of such polymer segment, most preferably an isotacticpolypropylene block.

The polymers of the invention can have a melt index, 12, from 0.01 to2000 g/10 minutes, preferably from 0.01 to 1000 g/10 minutes, morepreferably from 0.01 to 500 g/10 minutes, and especially from 0.01 to100 g/10 minutes. Desirably, the invented polymers can have molecularweights, M_(w), from 1,000 g/mole to 5,000,000 g/mole, preferably from1000 g/mole to 1,000,000, more preferably from 10,000 g/mole to 500,000g/mole, and especially from 10,000 g/mole to 300,000 g/mole. The densityof the invented polymers can be from 0.80 to 0.99 g/cm³ and preferablyfrom 0.85 g/cm³ to 0.97 g/cm³.

The polymers of the invention may be differentiated from conventional,random copolymers, physical blends of polymers, and block copolymersprepared via sequential monomer addition, fluxional catalysts, anionicor cationic living polymerization techniques. In particular, compared toa random copolymer of the same monomers and monomer content atequivalent crystallinity or modulus, the polymers of the inventiongenerally have better (higher) heat resistance as measured by meltingpoint, higher TMA penetration temperature, higher high-temperaturetensile strength, and/or higher high-temperature torsion modulus asdetermined by dynamic mechanical analysis. Compared to a randomcopolymer comprising the same monomers and monomer content, theinventive polymers generally have higher tear strength, faster setup dueto higher crystallization (solidification) temperature, better abrasionresistance, and better oil and filler acceptance.

Moreover, the present polymers may be prepared using techniques toinfluence the degree or level of blockiness. That is the amount oftacticity and length of each polymer block or segment can be altered bycontrolling the ratio and type of catalysts and shuttling agent as wellas the temperature of the polymerization, and other polymerizationvariables. A surprising benefit of this phenomenon is the discovery thatas the degree of blockiness is increased, the optical properties, tearstrength, and melt properties of the resulting polymer are generallyimproved. In particular, haze decreases while clarity and tear strengthincrease as the average number of blocks in the polymer increases whilemelt viscosity generally decreases. By selecting shuttling agents andcatalyst combinations having the desired chain transferring ability(high rates of shuttling with low levels of chain termination) otherforms of polymer termination are effectively suppressed. Accordingly,little if any β-hydride elimination is observed in the polymerization ofcomonomer mixtures according to the invention.

Another surprising benefit of the invention is that polymers whereinchain ends are highly tactic can be selectively prepared. In certainapplications this is desirable because reducing the relative quantity ofpolymer that terminates with an atactic block reduces the intermoleculardilutive effect on crystalline regions. This result can be obtained bychoosing chain shuttling agents and catalysts having an appropriateresponse to hydrogen or other chain terminating agents. Specifically, ifthe catalyst which produces highly tactic polymer is more susceptible tochain termination (such as by use of hydrogen) than the catalystresponsible for producing the atactic polymer segment, then the highlytactic polymer segments will preferentially populate the terminalportions of the polymer. Not only are the resulting terminated groupstactic, but upon termination, the tactic polymer forming catalyst siteis once again available for reinitiation of polymer formation. Theinitially formed polymer is therefore another tactic polymer segment.Accordingly, both ends of the resulting multi-block copolymer arepreferentially tactic.

Additional components of the present formulations usefully employedaccording to the present invention include various other ingredients inamounts that do not detract from the properties of the resultantcomposition. These ingredients include, but are not limited toactivators, such as calcium or magnesium oxide; fatty acids such asstearic acid and salts thereof; fillers and reinforcers such as calciumor magnesium carbonate, silica, and aluminum silicates; plasticizerssuch as dialkyl esters of dicarboxylic acids; antidegradants; softeners;waxes; and pigments.

Applications and End Uses

The polymers of the invention can be useful employed in a variety ofconventional thermoplastic fabrication processes to produce usefularticles, including objects comprising at least one film layer, such asa monolayer film, or at least one layer in a multilayer film prepared bycast, blown, calendered, or extrusion coating processes; moldedarticles, such as blow molded, injection molded, or rotomolded articles;extrusions; fibers; and woven or non-woven fabrics. Thermoplasticcompositions comprising the present polymers, include blends with othernatural or synthetic polymers, additives, reinforcing agents, ignitionresistant additives, antioxidants, stabilizers, colorants, extenders,crosslinkers, blowing agents, and plasticizers. Of particular utilityare multi-component fibers such as core/sheath fibers, having an outersurface layer, comprising at least in part, one or more polymers of theinvention.

Fibers that may be prepared from the present polymers or blends includestaple fibers, tow, multicomponent, sheath/core, twisted, andmonofilament. Suitable fiber forming processes include spinbonded, meltblown techniques, as disclosed in U.S. Pat. Nos. 4,430,563, 4,663,220,4,668,566, and 4,322,027, gel spun fibers as disclosed in U.S. Pat. No.4,413,110, woven and nonwoven fabrics, as disclosed in U.S. Pat. No.3,485,706, or structures made from such fibers, including blends withother fibers, such as polyester, nylon or cotton, thermoformed articles,extruded shapes, including profile extrusions and co-extrusions,calendared articles, and drawn, twisted, or crimped yarns or fibers. Thenew polymers described herein are also useful for wire and cable coatingoperations, as well as in sheet extrusion for vacuum forming operations,and forming molded articles, including the use of injection molding,blow molding process, or rotomolding processes. Compositions comprisingthe invented polymers can also be formed into fabricated articles suchas those previously mentioned using conventional polyolefin processingtechniques which are well known to those skilled in the art ofpolyolefin processing.

Dispersions (both aqueous and non-aqueous) can also be formed using thepresent polymers or formulations comprising the same. Frothed foamscomprising the invented polymers can also be formed, as disclosed in PCTapplication No. 2004/027593, filed Aug. 25, 2004. The polymers may alsobe crosslinked by any known means, such as the use of peroxide, electronbeam, silane, azide, or other cross-linking technique. The polymers canalso be chemically modified, such as by grafting (for example by use ofmaleic anhydride (MAH), silanes, or other grafting agent), halogenation,amination, sulfonation, or other chemical modification.

Additives and adjuvants may be included in any formulation comprisingthe present polymers. Suitable additives include fillers, such asorganic or inorganic particles, including clays, talc, titanium dioxide,zeolites, powdered metals, organic or inorganic fibers, including carbonfibers, silicon nitride fibers, steel wire or mesh, and nylon orpolyester cording, nano-sized particles, clays, and so forth;tackifiers, oil extenders, including paraffinic or napthelenic oils; andother natural and synthetic polymers, including other polymers accordingto the invention.

Suitable polymers for blending with the polymers of the inventioninclude thermoplastic and non-thermoplastic polymers including naturaland synthetic polymers. Exemplary polymers for blending includepolypropylene, (both impact modifying polypropylene, isotacticpolypropylene, atactic polypropylene, and random ethylene/propylenecopolymers), conventional poly-4-methyl-1-pentene, various types ofpolyethylene, including high pressure, free-radical LDPE, Ziegler NattaLLDPE, metallocene PE, including multiple reactor PE (“in reactor”blends of Ziegler-Natta PE and metallocene PE, such as productsdisclosed in U.S. Pat. Nos. 6,545,088, 6,538,070, 6,566,446, 5,844,045,5,869,575, and 6,448,341, ethylene-vinyl acetate (EVA), ethylene/vinylalcohol copolymers, polystyrene, impact modified polystyrene, ABS,styrene/butadiene block copolymers and hydrogenated derivatives thereof(SBS and SEBS), and thermoplastic polyurethanes. Homogeneous polymerssuch as olefin plastomers and elastomers, ethylene and propylene-basedcopolymers (for example polymers available under the trade designationVERSIFY™ available from The Dow Chemical Company and VISTAMAXX™available from ExxonMobil can also be useful as components in blendscomprising the present polymers.

Suitable end uses for the foregoing products include elastic films andfibers; molded goods, such as tooth brush handles and appliance parts;profiles; auto parts and profiles; foam goods (both open and closedcell); coated fabrics; and viscosity index modifiers, also known as pourpoint modifiers, for lubricants.

Particularly desirable blends are thermoplastic polyolefin blends (TPO),thermoplastic elastomer blends (TPE), thermoplastic vulcanisites (TPV)and styrenic polymer blends. TPE and TPV blends may be prepared bycombining the invented multi-block polymers, including functionalized orunsaturated derivatives thereof with an optional rubber, includingconventional block copolymers, especially an SBS block copolymer, andoptionally a crosslinking or vulcanizing agent. TPO blends are generallyprepared by blending the invented multi-block copolymers with apolyolefin, and optionally a crosslinking or vulcanizing agent. Theforegoing blends may be used in forming a molded object, and optionallycrosslinking the resulting molded article. A similar procedure usingdifferent components has been previously disclosed in U.S. Pat. No.6,797,779.

Suitable conventional block copolymers for this application desirablypossess a Mooney viscosity (ML 1+4 @ 100° C.) in the range from 10 to135, more preferably from 25 to 100, and most preferably from 30 to 80.Suitable polyolefins especially include linear or low densitypolyethylene, polypropylene (including atactic, isotactic, syndiotacticand impact modified versions thereof) and poly(4-methyl-1-pentene).Suitable styrenic polymers include polystyrene, rubber modifiedpolystyrene (HIPS), styrene/acrylonitrile copolymers (SAN), rubbermodified SAN (ABS or AES) and styrene maleic anhydride copolymers.

The blends may be prepared by mixing or kneading the respectivecomponents at a temperature around or above the melt point temperatureof one or both of the components. For most multiblock copolymers, thistemperature may be above 130° C., most generally above 145° C., and mostpreferably above 150° C. Typical polymer mixing or kneading equipmentthat is capable of reaching the desired temperatures and meltplastifying the mixture may be employed. These include mills, kneaders,extruders (both single screw and twin-screw), Banbury mixers, andcalenders. The sequence of mixing and method may depend on the finalcomposition. A combination of Banbury batch mixers and continuous mixersmay also be employed, such as a Banbury mixer followed by a mill mixerfollowed by an extruder. Typically, a TPE or TPV composition will have ahigher loading of cross-linkable polymer (typically the conventionalblock copolymer containing unsaturation) compared to TPO compositions.Generally, for TPE and TPV compositions, the weight ratio of blockcopolymer to multi-block copolymer maybe from 90:10 to 10:90, morepreferably from 80:20 to 20:80, and most preferably from 75:25 to 25:75.For TPO applications, the weight ratio of multi-block copolymer topolyolefin may be from 959:5 to 5:95, more preferably from 90:10 to10:90. For modified styrenic polymer applications, the weight ratio ofmulti-block copolymer to polyolefin may also be from 95:5 to 5:95, morepreferably from 90:10 to 10:90. The ratios may be changed by changingthe viscosity ratios of the various components. There is considerableliterature illustrating techniques for changing the phase continuity bychanging the viscosity ratios of the constituents of a blend and aperson skilled in this art may consult if necessary.

The blend compositions may contain processing oils, plasticizers, andprocessing aids. Rubber processing oils have a certain ASTM designationsand paraffinic, napthenic or aromatic process oils are all suitable foruse. Generally from 0 to 150 parts, more preferably 0 to 100 parts, andmost preferably from 0 to 50 parts of oil per 100 parts of total polymerare employed. Higher amounts of oil may tend to improve the processingof the resulting product at the expense of some physical properties.Additional processing aids include conventional waxes, fatty acid salts,such as calcium stearate or zinc stearate, (poly)alcohols includingglycols, (poly)alcohol ethers, including glycol ethers, (poly)esters,including (poly)glycol esters, and metal salt-, especially Group 1 or 2metal or zinc-, salt derivatives thereof.

It is known that non-hydrogenated rubbers such as those comprisingpolymerized forms of butadiene or isoprene, including block copolymers(here-in-after diene rubbers), have lower resistance to UV, ozone, andoxidation, compared to mostly or highly saturated rubbers. Inapplications such as tires made from compositions containing higherconcentrations of diene based rubbers, it is known to incorporate carbonblack to improve rubber stability, along with anti-ozone additives andanti-oxidants. For conventional TPO, TPV, and TPE applications, carbonblack is the additive of choice for UV absorption and stabilizingproperties. Representative examples of carbon blacks include ASTM N110,N121, N220, N231, N234, N242, N293, N299, S315, N326, N330, M332, N339,N343, N347, N351, N358, N375, N539, N550, N582, N630, N642, N650, N683,N754, N762, N765, N774, N787, N907, N908, N990 and N991. These carbonblacks have iodine absorptions ranging from 9 to 145 g/kg and averagepore volumes ranging from 10 to 150 cm³/100 g. Generally, smallerparticle sized carbon blacks are employed, to the extent costconsiderations permit.

Compositions, including thermoplastic blends according to the inventionmay also contain anti-ozonants or anti-oxidants that are known to thechemist of ordinary skill. The anti-ozonants may be physical protectantssuch as waxy materials that come to the surface and protect the partfrom oxygen or ozone or they may be chemical protectors that react withoxygen or ozone. Suitable chemical protectors include styrenatedphenols, butylated octylated phenol, butylated di(dimethylbenzyl)phenol,p-phenylenediamines, butylated reaction products of p-cresol anddicyclopentadiene (DCPD), polyphenolic antioxidants, hydroquinonederivatives, quinoline, diphenylene antioxidants, thioesterantioxidants, and blends thereof. Some representative trade names ofsuch products are Wingstay™ S antioxidant, Polystay™ 100 antioxidant,Polystay™ 100 AZ antioxidant, Polystay™ 200 antioxidant, Wingstay™ Lantioxidant, Wingstay™ LHLS antioxidant, Wingstay™ K antioxidant,Wingstay™ 29 antioxidant, Wingstaym SN-1 antioxidant, and Irganox™antioxidants. In some applications, the anti-oxidants and anti-ozonantsused will preferably be non-staining and non-migratory.

For providing additional stability against UV radiation, hindered aminelight stabilizers (HALS) and UV absorbers may be also used. Suitableexamples include Tinuvin™ 123, Tinuvin™ 144, Tinuvin™ 622, Tinuvin™ 765,Tinuvin™ 770, and Tinuvin™ 780, available from Ciba Specialty Chemicals,and Chemisorb™ T944, available from Cytex Plastics, Houston Tex., USA. ALewis acid may be additionally included with a HALS compound in order toachieve superior surface quality, as disclosed in U.S. Pat. No.6,051,681.

For some compositions, additional mixing process may be employed topre-disperse the anti-oxidants, anti-ozonants, carbon black, UVabsorbers, and/or light stabilizers to form a masterbatch, andsubsequently to form polymer blends there from.

The multi-block copolymers of the invention as well as blends thereofpossess improved processability compared to prior art compositions, due,it is believed, to lower melt viscosity. Thus, the composition or blenddemonstrates an improved surface appearance, especially when formed intoa molded or extruded article. At the same time, the present compositionsand blends thereof uniquely possess improved melt strength properties,thereby allowing the present multi-block copolymers and blends thereof,especially TPO blends, to be usefully employed in foam and thermoformingapplications where melt strength is currently inadequate.

Thermoplastic compositions according to the invention may also containorganic or inorganic fillers or other additives such as starch, talc,calcium carbonate, glass fibers, polymeric fibers (including nylon,rayon, cotton, polyester, and polyaramide), metal fibers, flakes orparticles, expandable layered silicates, phosphates or carbonates, suchas clays, mica, silica, alumina, aluminosilicates or aluminophosphates,carbon whiskers, carbon fibers, nanoparticles including nanotubes,wollastonite, graphite, zeolites, and ceramics, such as silicon carbide,silicon nitride or titanias. Silane based or other coupling agents mayalso be employed for better filler bonding.

The thermoplastic compositions of this invention, including theforegoing blends, may be processed by conventional molding techniquessuch as injection molding, extrusion molding, thermoforming, slushmolding, over molding, insert molding, blow molding, and othertechniques. Films, including multi-layer films, may be produced by castor tentering processes, including blown film processes.

Testing Methods

In the foregoing characterizing disclosure and the examples that follow,the following analytical techniques may be employed:

DSC

Differential Scanning Calorimetry results may be determined using a TAImodel Q1000 DSC equipped with an RCS cooling accessory and anautosampler. A nitrogen purge gas flow of 50 ml/min is used. The sampleis pressed into a thin film and melted in the press at 175° C. and thenair-cooled to room temperature (25° C.). 3-10 mg Of material is then cutinto a 6 mm diameter disk, accurately weighed, placed in a lightaluminum pan (ca 50 mg), and then crimped shut. The thermal behavior ofthe sample is investigated with the following temperature profile. Thesample is rapidly heated to 180° C. and held isothermal for 3 minutes inorder to remove any previous thermal history. The sample is then cooledto −40° C. at 10° C./min cooling rate and held at −40° C. for 3 minutes.The sample is then heated to 150° C. at 10° C./min. heating rate. Thecooling and second heating curves are recorded.

The DSC melting peak is measured as the maximum in heat flow rate (W/g)with respect to the linear baseline drawn between −30° C. and end ofmelting. The heat of fusion is measured as the area under the meltingcurve between −30° C. and the end of melting using a linear baseline.

Abrasion Resistance

Abrasion resistance is measured on compression molded plaques accordingto ISO 4649. The average value of 3 measurements is reported. Plaquesfor the test are 6.4 mm thick and compression molded using a hot press(Carver Model #4095-4PR1001R). The pellets are placed betweenpolytetrafluoroethylene sheets, heated at 190° C. at 55 psi (380 kPa)for 3 minutes, followed by 1.3 MPa for 3 minutes, and then 2.6 MPa for 3minutes. Next the plaques are cooled in the press with running coldwater at 1.3 MPa for 1 minute and removed for testing.

GPC Method

The gel permeation chromatographic system consists of either a PolymerLaboratories Model PL-210 or a Polymer Laboratories Model PL-220instrument. The column and carousel compartments are operated at 140° C.Three Polymer Laboratories 10-micron Mixed-B columns are used. Thesolvent is 1,2,4 trichlorobenzene. The samples are prepared at aconcentration of 0.1 grams of polymer in 50 milliliters of solventcontaining 200 ppm of butylated hydroxytoluene (BHT). Samples areprepared by agitating lightly for 2 hours at 160° C. The injectionvolume used is 100 microliters and the flow rate is 1.0 ml/minute.

Calibration of the GPC column set is performed with 21 narrow molecularweight distribution polystyrene standards with molecular weights rangingfrom 580 to 8,400,000, arranged in 6 “cocktail” mixtures with at least adecade of separation between individual molecular weights. The standardsare purchased from Polymer Laboratories (Shropshire, UK). Thepolystyrene standards are prepared at 0.025 grams in 50 milliliters ofsolvent for molecular weights equal to or greater than 1,000,000, and0.05 grams in 50 milliliters of solvent for molecular weights less than1,000,000. The polystyrene standards are dissolved at 80° C. with gentleagitation for 30 minutes. The narrow standards mixtures are run firstand in order of decreasing highest molecular weight component tominimize degradation. The polystyrene standard peak molecular weightsare converted to polyethylene molecular weights using the followingequation (as described in Williams and Ward, J. Polym. Sci., Polym.Let., 6, 621 (1968)): M_(polyethylene)=0.431(M_(polystyrene)).

Polyetheylene equivalent molecular weight calculations are performedusing Viscotek TriSEC software Version 3.0.

Compression Set

Compression set is measured according to ASTM D 395. The sample isprepared by stacking 25.4 mm diameter round discs of 3.2 mm, 2.0 mm, and0.25 mm thickness until a total thickness of 12.7 mm is reached. Thediscs are cut from 12.7 cm×12.7 cm compression molded plaques moldedwith a hot press under the following conditions: zero pressure for 3 minat 190° C., followed by 86 MPa for 2 min at 190° C., followed by coolinginside the press with cold running water at 86 MPa.

Density

Samples for density measurement are prepared according to ASTM D 1928.Measurements are made within one hour of sample pressing using ASTMD792, Method B.

Flexural/Secant Modulus/Storage Modulus

Samples are compression molded using ASTM D 1928. Flexural and 2 percentsecant moduli are measured according to ASTM D-790. Storage modulus ismeasured according to ASTM D 5026-01 or equivalent technique.

Optical Properties

Films of 0.4 mm thickness are compression molded using a hot press(Carver Model #4095-4PR1001R). The pellets are placed betweenpolytetrafluoroethylene sheets, heated at 190° C. at 55 psi (380 kPa)for 3 min, followed by 1.3 MPa for 3 min, and then 2.6 MPa for 3 min.The film is then cooled in the press with running cold water at 1.3 MPafor 1 min. The compression molded films are used for opticalmeasurements, tensile behavior, recovery, and stress relaxation.

Clarity is measured using BYK Gardner Haze-gard as specified in ASTM D1746.

45° gloss is measured using BYK Gardner Glossmeter Microgloss 45° asspecified in ASTM D-2457

Internal haze is measured using BYK Gardner Haze-gard based on ASTM D1003 Procedure A. Mineral oil is applied to the film surface to removesurface scratches.

Melt Index

Melt index, or I₂, is measured in accordance with ASTM D 1238, Condition190° C./2.16 kg. Melt index, or I₁₀ is also measured in accordance withASTM D 1238, Condition 190° C./10 kg.

ATREF

Analytical temperature rising elution fractionation (ATREF) analysis isconducted according to the method described in U.S. Pat. No. 4,798,081.The composition to be analyzed is dissolved in trichlorobenzene andallowed to crystallize in a column containing an inert support(stainless steel shot) by slowly reducing the temperature to 20° C. at acooling rate of 0.1° C./min. The column is equipped with an infrareddetector. An ATREF chromatogram curve is then generated by eluting thecrystallized polymer sample from the column by slowly increasing thetemperature of the eluting solvent (trichlorobenzene) from 20 to 120° C.at a rate of 1.5° C./min.

¹³C NMR Analysis

The samples are prepared by adding approximately 3 g of a 50/50 mixtureof tetrachloroethane-d²/orthodichlorobenzene to 0.4 g sample in a 10 mmNMR tube. The samples are dissolved and homogenized by heating the tubeand its contents to 150° C. The data is collected using a JEOL Eclipse™400 MHz spectrometer or a Varian Unity PIUs™ 400 MHz spectrometer,corresponding to a ¹³C resonance frequency of 100.5 MHz. The data isacquired using 4000 transients per data file with a 6 second pulserepetition delay. To achieve minimum signal-to-noise for quantitativeanalysis, multiple data files are added together. The spectral width is25,000 Hz with a minimum file size of 32K data points. The samples areanalyzed at 130° C. in a 10 mm broad band probe. The comonomerincorporation is determined using Randall's triad method (Randall, J.C.; JMS-Rev. Macromol. Chem. Phys., C29, 201-317 (1989).

SPECIFIC EMBODIMENTS

The following specific embodiments of the invention and combinationsthereof are especially desirable and hereby delineated in order toprovide detailed disclosure for the appended claims.

1. A copolymer formed by polymerizing propylene, 4-methyl-1-pentene, oranother C₄₋₃₀ α-olefin in the presence of a composition comprising theadmixture or reaction product resulting from combining:

(A) a first olefin polymerization catalyst,

(B) a second olefin polymerization catalyst capable of preparing apolymer differing in tacticity from the polymer prepared by catalyst (A)under equivalent polymerization conditions, and

(C) a chain shuttling agent.

2. A copolymer formed by polymerizing propylene, 4-methyl-1-pentene, oranother C₄₋₃₀ α-olefin, and a copolymerizable comonomer in the presenceof a composition comprising the admixture or reaction product resultingfrom combining:

(A) a first olefin polymerization catalyst that under the conditions ofpolymerization forms a tactic polymer of one or more C₃₋₃₀ α-olefins,

(B) a second olefin polymerization catalyst that under the conditions ofpolymerization forms a polymer having a tacticity less than 95 percent,preferably less than 90 percent, more preferably less than 75 percent,and most preferably less than 50 percent of the polymer made by catalyst(A), and

(C) a chain shuttling agent.

3. A process for preparing a propylene containing multi-block copolymercomprising contacting propylene under addition polymerization conditionswith a composition comprising:

the admixture or reaction product resulting from combining:

(A) a first olefin polymerization catalyst,

(B) a second olefin polymerization catalyst capable of preparing apolymer differing in tacticity from the polymer prepared by catalyst (A)under equivalent polymerization conditions, and

(C) a chain shuttling agent.

4. A process for preparing a propylene containing multi-block copolymercomprising contacting propylene under addition polymerization conditionswith a composition comprising:

the admixture or reaction product resulting from combining:

A) a first olefin polymerization catalyst that under the conditions ofpolymerization forms tactic polypropylene,

(B) a second olefin polymerization catalyst that under the conditions ofpolymerization forms a polymer having a tacticity less than 95 percent,preferably less than 90 percent, more preferably less than 75 percent,and most preferably less than 50 percent of the polymer made by catalyst(A), and

(C) a chain shuttling agent.

5. A process for preparing a 4-methyl-1-pentene containing multi-blockcopolymer comprising contacting 4-methyl-1-pentene under additionpolymerization conditions with a composition comprising:

the admixture or reaction product resulting from combining:

(A) a first olefin polymerization catalyst,

(B) a second olefin polymerization catalyst capable of preparing apolymer differing in tacticity from the polymer prepared by catalyst (A)under equivalent polymerization conditions, and

(C) a chain shuttling agent.

6. A process for preparing a 4-methyl-1-pentene containing multi-blockcopolymer comprising contacting 4-methyl-1-pentene under additionpolymerization conditions with a composition comprising:

the admixture or reaction product resulting from combining:

A) a first olefin polymerization catalyst that under the conditions ofpolymerization forms a tactic 4-methyl-1-pentene homopolymer,

(B) a second olefin polymerization catalyst that under the conditions ofpolymerization forms a polymer having a tacticity less than 95 percent,preferably less than 90 percent, more preferably less than 75 percent,and most preferably less than 50 percent of the polymer made by catalyst(A), and

(C) a chain shuttling agent.

7. A multi-block copolymer comprising in polymerized form propylene,4-methyl-1-pentene, or another C₄₋₈ α-olefin, said copolymer containingtherein two or more, preferably three or more segments or blocksdiffering in tacticity and possessing a molecular weight distribution,Mw/Mn, of less than 3.0, more preferably less than 2.8.

8. A multi-block copolymer consisting essentially of propylene inpolymerized form, said copolymer containing therein two or more,preferably three or more segments or blocks differing in tacticity andpossessing a molecular weight distribution, Mw/Mn, of less than 3.0,more preferably less than 2.8.

9. A multi-block copolymer consisting essentially of 4-methyl-1-pentenein polymerized form, said copolymer containing therein two or more,preferably three or more segments or blocks differing in tacticity andpossessing a molecular weight distribution, Mw/Mn, of less than 3.0,more preferably less than 2.8.

10. A multi-block copolymer according to any one of embodiments 5-9containing therein four or more segments or blocks differing intacticity.

11. A functionalized derivative of the multi-block copolymer of any oneof embodiments 1, 2, 5-9 or made by the process of embodiment 3 or 4.

12. A functionalized derivative of the multi-block copolymer ofembodiment 10.

13. A homogeneous polymer mixture comprising: (1) an organic orinorganic polymer, preferably a homopolymer of propylene or ethyleneand/or a copolymer of ethylene and a copolymerizable comonomer, and (2)a multi-block copolymer according to any one of embodiments 1, 2, 5-9 ormade by the process of embodiment 3 or 4 of the present invention.

14. A polymer according to any one of embodiments 1, 2, 5-9 or made bythe process of embodiment 3 or 4, or a composition comprising the samein the form of a film, at least one layer of a multilayer film, at leastone layer of a laminated article, a foamed article, a fiber, a nonwovenfabric, an injection molded article, a blow molded article, or aroto-molded article.

15. A polymer according to embodiment 12 or a composition comprising thesame in the form of a film, at least one layer of a multilayer film, atleast one layer of a laminated article, a foamed article, a fiber, anonwoven fabric, an injection molded article, a blow molded article, ora roto-molded article.

16. A polymer mixture according to embodiment 13 or a compositioncomprising the same in the form of a film, at least one layer of amultilayer film, at least one layer of a laminated article, a foamedarticle, a fiber, a nonwoven fabric, an injection molded article, a blowmolded article, or a roto-molded article.

17. A copolymer according to embodiment 1 or 2 wherein the shuttlingagent is a trihydrocarbyl aluminum- or dihydrocarbyl zinc-compoundcontaining from 1 to 12 carbons in each hydrocarbyl group.

18. A copolymer according to embodiment 17 wherein the shuttling agentis triethylaluminum or diethylzinc.

19. A process according to embodiment 3 or 4 which is a continuousprocess.

20. A process according to embodiment 19 which is a solution process.

21. A process according to embodiment 20 wherein propylene is the onlymonomer polymerized.

The skilled artisan will appreciate that the invention disclosed hereinmay be practiced in the absence of any component, step or ingredientwhich has not been specifically disclosed.

EXAMPLES

The following examples are provided as further illustration of theinvention and are not to be construed as limiting. The term “overnight”,if used, refers to a time of approximately 16-18 hours, the term “roomtemperature”, refers to a temperature of 20-25° C., and the term “mixedalkanes” refers to a commercially obtained mixture of C₆₋₉ aliphatichydrocarbons available under the trade designation Isopar E®, from ExxonMobil Chemicals Inc. In the event the name of a compound herein does notconform to the structural representation thereof, the structuralrepresentation shall control. The synthesis of all metal complexes andthe preparation of all screening experiments were carried out in a drynitrogen atmosphere using dry box techniques. All solvents used wereHPLC grade and were dried before their use.

MMAO refers to modified methylalumoxane, a triisobutylaluminum modifiedmethylalumoxane available commercially from Akzo-Noble Corporation.

Catalyst (A1) is[N-(2,6-di(1-methylethyl)phenyl)amido)(2-isopropylphenyl)(α-naphthalen-2-diyl(6-pyridin-2-diyl)methane)]hafniumdimethyl, prepared according to the teachings of WO 2003/040195,WO/2004/024740, WO 2004/099268, and U.S. Ser. No. 10/429,024, filed May2, 2003.

Catalyst (B1) is(t-butylamido)dimethyl(3-pyrrolidinyl-1H-inden-1-yl)silanetitanium1,3-pentadiene, prepared according to the teachings of U.S. Pat. No.6,268,444.

Catalyst (B2) is[N-phenylamido)(2-isopropylphenyl)(α-naphthalen-2-diyl(6-pyridin-2-diyl)methane)]hafniumdimethyl, prepared according to the teachings of WO 2003/040195,WO/2004/024740, WO 2004/099268, and U.S. Ser. No. 10/429,024, filed May2, 2003.

Cocatalyst 1 A mixture of methyldi(C₁₄₋₁₈ alkyl)ammonium salts oftetrakis(pentafluorophenyl)borate (here-in-after armeenium borate),prepared by reaction of a long chain trialkylamine (Armeem™ M2HT,available from Akzo-Nobel, Inc.), HCl and Li[B(C₆F₅)₄], substantially asdisclosed in U.S. Pat. No. 5,919,983, Ex. 2.

Shuttling Agents The shuttling agents employed include diethylzinc (DEZ)and trioctylaluminum (TOA).

General High Throughput Parallel Polymerization Conditions

Polymerizations are conducted using a high throughput, parallelpolymerization reactor (PPR) available from Symyx technologies, Inc. andoperated substantially according to U.S. Pat. Nos. 6,248,540, 6,030,917,6,362,309, 6,306,658, and 6,316,663. Polymerizations are conducted at120° C. using 1.2 equivalents of cocatalyst 1 based on total catalystused (1.1 equivalents when MMAO is present). A series of polymerizationsare conducted in a parallel pressure reactor (PPR) comprising 48individual reactor cells in a 6×8 array that are fitted with apre-weighed glass tube. The working volume in each reactor cell is 6000μL. Each cell is temperature and pressure controlled with stirringprovided by individual stirring paddles. The monomer gas and quench gasare plumbed directly into the PPR unit and controlled by automaticvalves. Liquid reagents are robotically added to each reactor cell bysyringes and the reservoir solvent is mixed alkanes. The order ofaddition is mixed alkanes solvent (4 ml), monomers, cocatalyst,shuttling agent, and catalyst. After quenching with CO, the reactors arecooled and the glass tubes are unloaded. The tubes are transferred to acentrifuge/vacuum drying unit, and dried for 12 hours at 60° C. Thetubes containing dried polymer are weighed and the difference betweenthis weight and the tare weight gives the net yield of polymer.

Example 1

A 6-mL reaction vessel containing a glass vial insert is charged withmixed alkanes (3.295 mL), and then pressurized to 90 psi (0.63 MPa) withpropylene. Cocatalyst 1 (1.23 mM in toluene, 0.205 mL, 2.52 μmol) andDEZ (2.5 mM in toluene, 0.200 mL, 0.5 μmol) are sequentially added viasyringe. A mixture of catalyst A1 (1.0 mM in toluene, 0.10 mL, 100 mmol)and B1 (10 mM in toluene, 0.20 mL, 2.0 μmol) is added via syringe. After1200 seconds, the reaction is quenched by addition of CO. The glassinsert is removed and volatile components removed under vacuum. GPCreveals a PDI<2.0.

Example 2

A 6-mL reaction vessel containing a glass vial insert is charged withmixed alkanes (3.434 mL) and 4-methyl-1-pentene (2.00 ml). Cocatalyst 1(1.23 mM in toluene, 0.100 mL, 1.23 μmol) and TOA (2.5 mM in toluene,0.200 mL, 0.5 μmol) are sequentially added via syringe. A mixture ofcatalyst A1 (0.15 mM in toluene, 0.166 mL, 25 nmol) and B2 (10 mM intoluene, 0.100 mL, 1.0 μmol) is added via syringe. After 1200 seconds,the reaction is quenched by addition of CO. The glass insert is removedand volatile components removed under vacuum. GPC reveals PDI<2.0.

Example 3

A 6-mL reaction vessel containing a glass vial insert is charged withmixed alkanes (3.434 mL), and then pressurized to 90 psi (0.63 MPa) withpropylene. Cocatalyst 1 (1.23 mM in toluene, 0.100 mL, 1.23 μmol) andTOA (2.5 mM in toluene, 0.200 mL, 0.5 μmol) are sequentially added viasyringe. A mixture of catalyst A1 (0.15 mM in toluene, 0.166 mL, 25nmol) and B2 (10 mM in toluene, 0.100 mL, 1.0 μmol) is added viasyringe. After 1000 seconds, the reaction is quenched by addition of CO.The glass insert is removed and volatile components removed undervacuum. GPC reveals PDI<2.0.

Comparative A

A 6-mL reaction vessel containing a glass vial insert is charged withmixed alkanes (3.454 μL), and then pressurized to 90 psi (0.63 MPa) withpropylene. Cocatalyst 1 (1.23 mM in toluene, 0.148 mL, 1.82 lμmol) andMMAO (51 mM in toluene, 0.148 mL, 7.6 μmol) are sequentially added viasyringe. A mixture of Catalyst A1 (0.15 mM in toluene, 0.10 mL, 15 nmol)and B1 (10 mM in toluene, 0.15 mL, 1.5 μmol) is added via syringe. Noshuttling agent is employed. After 500 seconds, the reaction is quenchedby addition of CO. The glass insert is removed and volatile componentsremoved under vacuum. GPC reveals PDI>2.0.

Comparative B

A 6-mL reaction vessel containing a glass vial insert is charged withmixed alkanes (3.454 mL), and then pressurized to 90 psi (0.63 MPa) withpropylene. Cocatalyst 1 (1.2 mM in toluene, 0.148 mL, 1.8 μmol) and MMAO(51 mM in toluene, 0.148 mL, 7.6 μmol) are sequentially added viasyringe. A mixture of catalyst A1 (0.15 mM in toluene, 0.10 mL, 15 nmol)and B2 (10 mM in toluene, 0.15 mL, 1.5 μmol) is added via syringe. After850 seconds, the reaction is quenched by addition of CO. GPC revealsPDI>2.0.

Examples 1-3 demonstrate the synthesis of linear block copolymers by thepresent invention as evidenced by the formation of a very narrow MWD,essentially monomodal copolymer when DEZ or TOA is present and abimodal, broad molecular weight distribution product (a mixture ofgenerally isotactic and atactic polymers) in the absence of chainshuttling agent. Due to the fact that Catalyst (A1) has differentstereospecificity characteristics than Catalyst B1, the different blocksor segments of the resulting multi-block copolymers are distinguishablebased on tacticity.

Examples of Continuous Solution Polymerization

Continuous solution polymerizations are carried out in a computercontrolled autoclave reactor equipped with an internal stirrer. Purifiedmixed alkanes solvent (Isopar™ E available from ExxonMobil, Inc.),propylene, and hydrogen (where used) are supplied to a 3.8 L reactorequipped with a jacket for temperature control and an internalthermocouple. The solvent feed to the reactor is measured by a mass-flowcontroller. A variable speed diaphragm pump controls the solvent flowrate and pressure to the reactor. At the discharge of the pump, a sidestream is taken to provide flush flows for the catalyst and cocatalyst 1injection lines and the reactor agitator. These flows are measured byMicro-Motion mass flow meters and controlled by control valves or by themanual adjustment of needle valves. The remaining solvent is combinedwith propylene and hydrogen (where used) and fed to the reactor. A massflow controller is used to deliver hydrogen to the reactor as needed.The temperature of the solvent/monomer solution is controlled by use ofa heat exchanger before entering the reactor. Temperature of the reactoris maintained at the desired temperature, typically between 70-140° C.This stream enters the bottom of the reactor. The catalyst componentsolutions are metered using pumps and mass flow meters and are combinedwith the catalyst flush solvent and introduced into the bottom of thereactor. The reactor is run liquid-full at 500 psig (3.45 MPa) withvigorous stirring. Product is removed through exit lines at the top ofthe reactor. All exit lines from the reactor are steam traced andinsulated. Polymerization is stopped by the addition of a small amountof water into the exit line along with any stabilizers or otheradditives and passing the mixture through a static mixer. The productstream is then heated by passing through a heat exchanger beforedevolatilization. The polymer product is recovered by extrusion using adevolatilizing extruder and water cooled pelletizer.

The reactor temperature and monomer concentration are used to controlthe tacticity of the polymer segment or block produced by each catalyst,enabling production of polymer segments or blocks from the two catalyststhat are distinguishable based on tacticity. Suitable blocks comprisingisotactic polypropylene and atactic polypropylene can be produced byachieving the correct propylene concentration, catalyst ratios, andamount of chain shuttling agent (DEZ) added. Monomer conversion isregulated at the desired level by adjusting the feeds of the catalysts.The overall composition of the polymer, meaning the relative amounts ofthe two types of differentiated polymer segments, is controlled bymodifying either the catalyst feed ratio or the reactor temperature ormonomer concentration. Hydrogen and/or DEZ is used to control molecularweight of the polymer. When hydrogen alone is used for control ofmolecular weight, the product can display bimodal molecular weight andcomposition distributions. This copolymer blend can be separated bytechniques commonly used by those skilled in the art. Conversely, whenDEZ is used for molecular weight control, the copolymer displays narrowmolecular weight and composition distributions consistent with amulti-block polymer.

The inventive polymer samples from the above continuous solutionpolymerization procedure can display several enhanced characteristicsrelative to comparative examples or normal propylene homopolymers. Forexample, high temperature resistance properties, as evidenced by TMAtemperature testing, pellet blocking strength, high temperaturerecovery, high temperature compression set and storage modulus ratio,G′(25° C.)/G′(100° C.), can all be achieved.

1. A copolymer formed by polymerizing propylene, 4-methyl-1-pentene, oranother C₄₋₈ α-olefin in the presence of a composition comprising theadmixture or reaction product resulting from combining: (A) a firstolefin polymerization catalyst, (B) a second olefin polymerizationcatalyst capable of preparing a polymer differing in tacticity from thepolymer prepared by catalyst (A) under equivalent polymerizationconditions, and (C) a chain shuttling agent.
 2. A copolymer formed bypolymerizing propylene, 4-methyl-1-pentene, or another C₄₋₈ α-olefin,and a copolymerizable comonomer in the presence of a compositioncomprising the admixture or reaction product resulting from combining:(A) a first olefin polymerization catalyst that under the conditions ofpolymerization forms a tactic polymer of one or more C₃₋₃₀ α-olefins,(B) a second olefin polymerization catalyst that under the conditions ofpolymerization forms a polymer having a tacticity less than 95 percentof the polymer formed by catalyst (A), and (C) a chain shuttling agent.3. A process for preparing a propylene containing multi-block copolymercomprising contacting propylene under addition polymerization conditionswith a composition comprising: the admixture or reaction productresulting from combining: (A) a first olefin polymerization catalyst,(B) a second olefin polymerization catalyst capable of preparing apolymer differing in tacticity from the polymer prepared by catalyst (A)under equivalent polymerization conditions, and (C) a chain shuttlingagent.
 4. A process for preparing a propylene containing multi-blockcopolymer comprising contacting propylene under addition polymerizationconditions with a composition comprising: the admixture or reactionproduct resulting from combining: A) a first olefin polymerizationcatalyst that under the conditions of polymerization forms tacticpolypropylene, (B) a second olefin polymerization catalyst that underthe conditions of polymerization forms a polymer having a tacticity lessthan 95 percent of catalyst (A), and (C) a chain shuttling agent.
 5. Aprocess for preparing a 4-methyl-1-pentene containing multi-blockcopolymer comprising contacting 4-methyl-1-pentene under additionpolymerization conditions with a composition comprising: the admixtureor reaction product resulting from combining: (A) a first olefinpolymerization catalyst, (B) a second olefin polymerization catalystcapable of preparing a polymer differing in tacticity from the polymerprepared by catalyst (A) under equivalent polymerization conditions, and(C) a chain shuttling agent.
 6. A process for preparing a4-methyl-1-pentene containing multi-block copolymer comprisingcontacting 4-methyl-1-pentene under addition polymerization conditionswith a composition comprising: the admixture or reaction productresulting from combining: A) a first olefin polymerization catalyst thatunder the conditions of polymerization forms a tactic 4-methyl-1-pentenehomopolymer, (B) a second olefin polymerization catalyst that under theconditions of polymerization forms a polymer having a tacticity lessthan 95 percent of catalyst (A), and (C) a chain shuttling agent.
 7. Amulti-block copolymer comprising in polymerized form propylene,4-methyl-1-pentene, or another C₄₋₈ α-olefin, said copolymer containingtherein two or more blocks differing in tacticity and possessing amolecular weight distribution, Mw/Mn, of less than 3.0.
 8. A multi-blockcopolymer consisting essentially of propylene in polymerized form, saidcopolymer containing therein two or more segments or blocks differing intacticity and possessing a molecular weight distribution, Mw/Mn, of lessthan 3.0.
 9. A multi-block copolymer consisting essentially of4-methyl-1-pentene in polymerized form, said copolymer containingtherein two or more segments or blocks differing in tacticity andpossessing a molecular weight distribution, Mw/Mn, of less than 3.0. 10.A multi-block copolymer according to any one of claims 5-9 containingtherein four or more segments or blocks differing in tacticity.
 11. Afunctionalized derivative of the multi-block copolymer of any one ofclaims 1, 2, 5-9 or made by the process of claim 3 or
 4. 12. Afunctionalized derivative of the multi-block copolymer of claim
 10. 13.A homogeneous polymer mixture comprising: (1) an organic or inorganicpolymer and (2) a multi-block copolymer according to any one of claims1, 2, 5-9 or made by the process of claim 3 or 4 of the presentinvention.
 14. A polymer according to any one of claims 1, 2, 5-9 ormade by the process of claim 3 or 4, or a composition comprising thesame in the form of a film, at least one layer of a multilayer film, atleast one layer of a laminated article, a foamed article, a fiber, anonwoven fabric, an injection molded article, a blow molded article, ora roto-molded article.
 15. A polymer according to claim 12 or acomposition comprising the same in the form of a film, at least onelayer of a multilayer film, at least one layer of a laminated article, afoamed article, a fiber, a nonwoven fabric, an injection molded article,a blow molded article, or a roto-molded article.
 16. A polymer mixtureaccording to claim 13 or a composition comprising the same in the formof a film, at least one layer of a multilayer film, at least one layerof a laminated article, a foamed article, a fiber, a nonwoven fabric, aninjection molded article, a blow molded article, or a roto-moldedarticle.
 17. A copolymer according to claim 1 or 2 wherein the shuttlingagent is a trihydrocarbyl aluminum- or dihydrocarbyl zinc-compoundcontaining from 1 to 12 carbons in each hydrocarbyl group.
 18. Acopolymer according to claim 17 wherein the shuttling agent istriethylaluminum or diethylzinc.
 19. A process according to claim 3 or 4which is a continuous process.
 20. A process according to claim 19 whichis a solution process.
 21. A process according to claim 20 whereinpropylene is the only monomer polymerized.